diff --git a/NEWS.md b/NEWS.md
index cfbb185d..022700d4 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -6,6 +6,10 @@
   * exclusions for less severer conditions when more severer conditions are flagged
   * Improved POA, NPOA, and EXEMPTPOA.  This came about from #20.
 
+* Make internal data.frame tool `mdcr_duplicated` data.table aware.
+
+* Elixhauser (Quan 2005) - added missing ICD-10 codes to the mappings
+
 ## New Features
 
 * `comorbidities()` will return a `tibble` with the input data is a `tbl_df`
diff --git a/R/sysdata.rda b/R/sysdata.rda
index 84ef243e..c8fa0b23 100644
Binary files a/R/sysdata.rda and b/R/sysdata.rda differ
diff --git a/R/utilities.R b/R/utilities.R
index 42c14aec..c92fa74e 100644
--- a/R/utilities.R
+++ b/R/utilities.R
@@ -132,7 +132,10 @@ mdcr_setnames <- function(x, old, new, ...) {
 mdcr_duplicated <- function(x, by = seq_along(x), ...) {
   stopifnot(is.data.frame(x))
   if (requireNamespace("data.table", quietly = TRUE) && inherits(x, "data.table")) {
-    rtn <- duplicated(x, by = by, ...)
+    # Flag this frame as data.table-aware so duplicated.data.table uses its
+    # optimized path instead of falling back to duplicated.data.frame.
+    .datatable.aware <- TRUE
+    rtn <- utils::getFromNamespace(x = 'duplicated.data.table', ns = "data.table")(x, by = by, ...)
   } else {
     rtn <- duplicated(x[, by, drop = FALSE], ...)
   }
diff --git a/data-raw/build_sysdata.R b/data-raw/build_sysdata.R
index a016a529..8a0d4815 100644
--- a/data-raw/build_sysdata.R
+++ b/data-raw/build_sysdata.R
@@ -52,6 +52,9 @@
 ..mdcr_internal_elixhauser_poa..          <- readRDS("./elixhauser/elixhauser_poa.rds")
 ..mdcr_internal_elixhauser_codes..        <- readRDS("./elixhauser/elixhauser_codes.rds")
 
+
+# All internl data sets need to have the ..mdcr_internal_ prefix and .. suffix.
+# This is expected in tests and in use within the package.
 usethis::use_data(
     ..mdcr_internal_pccc_codes..
   , ..mdcr_internal_pccc_conditions..
diff --git a/data-raw/elixhauser/regex_based_on_quan2005.txt b/data-raw/elixhauser/regex_based_on_quan2005.txt
index 84105d95..32f5065a 100644
--- a/data-raw/elixhauser/regex_based_on_quan2005.txt
+++ b/data-raw/elixhauser/regex_based_on_quan2005.txt
@@ -152,6 +152,11 @@ DEPRESS             | 9    | 1  | quan2005       | ^296\.[2,3,5]
 DEPRESS             | 9    | 1  | quan2005       | ^300\.4
 DEPRESS             | 9    | 1  | quan2005       | ^309
 DEPRESS             | 9    | 1  | quan2005       | ^311
+DEPRESS             | 10   | 1  | quan2005       | ^F20\.4
+DEPRESS             | 10   | 1  | quan2005       | ^F31\.[3-5]
+DEPRESS             | 10   | 1  | quan2005       | ^F3[2-3]
+DEPRESS             | 10   | 1  | quan2005       | ^F34\.1
+DEPRESS             | 10   | 1  | quan2005       | ^F4[1-3]\.2
 DM                  | 10   | 1  | quan2005       | ^E1[0-4]\.[0,1,9]
 DM                  | 9    | 1  | ahrq_web       | ^250\.[0-3]
 DM                  | 9    | 1  | ahrq_web       | ^648\.0
@@ -191,6 +196,7 @@ HTN_UNCX            | 9    | 1  | ahrq_web       | ^642\.0
 HTN_UNCX            | 9    | 1  | elixhauser1988 | ^401\.[1,9]
 HTN_UNCX            | 9    | 1  | quan2005       | ^401
 HYPOTHY             | 10   | 1  | quan2005       | ^E0[0-3]
+HYPOTHY             | 10   | 1  | quan2005       | ^E89\.0
 HYPOTHY             | 9    | 1  | ahrq_web       | ^243
 HYPOTHY             | 9    | 1  | ahrq_web       | ^244\.[0-2,8,9]
 HYPOTHY             | 9    | 1  | elixhauser1988 | ^243
diff --git a/tests/test-asserts.R b/tests/test-asserts.R
index d2fe0400..9347c154 100644
--- a/tests/test-asserts.R
+++ b/tests/test-asserts.R
@@ -30,8 +30,6 @@ stopifnot(
   t01b = !("assert_scalar_logical" %in% getNamespaceExports("medicalcoder"))
 )
 
-# the method should only be used within methods and the error messages are
-# controlled:
 common_args <- list(data = mdcr, method = "pccc_v3.1", icd.codes = "code", poa = 1L)
 
 t02a <- tryCatchError(do.call(comorbidities, args = c(common_args, list(full.codes = TRUE))))
diff --git a/tests/test-charlson-codes.R b/tests/test-charlson-codes.R
deleted file mode 100644
index 345a877b..00000000
--- a/tests/test-charlson-codes.R
+++ /dev/null
@@ -1,64 +0,0 @@
-library(medicalcoder)
-
-# verify that the internal data set is a data.frame, and only a data.frame, not
-# a data.table, not a tibble
-stopifnot( inherits(medicalcoder:::..mdcr_internal_charlson_codes.., "data.frame"))
-stopifnot(!inherits(medicalcoder:::..mdcr_internal_charlson_codes.., "data.table"))
-stopifnot(!inherits(medicalcoder:::..mdcr_internal_charlson_codes.., "tbl_df"))
-
-stopifnot(
-  identical(
-    names(medicalcoder:::..mdcr_internal_charlson_codes..),
-    c("code_id", "condition", "charlson_cdmf2019", "charlson_deyo1992", "charlson_quan2005", "charlson_quan2011")
-  )
-)
-
-stopifnot(
-  identical(
-    sapply(medicalcoder:::..mdcr_internal_charlson_codes.., class),
-    c(code_id = "integer",
-      condition = "character",
-      charlson_cdmf2019 = "integer",
-      charlson_deyo1992 = "integer",
-      charlson_quan2005 = "integer",
-      charlson_quan2011 = "integer"
-    )
-  )
-)
-
-stopifnot( inherits(get_charlson_codes(), "data.frame"))
-stopifnot(!inherits(get_charlson_codes(), "data.table"))
-stopifnot(!inherits(get_charlson_codes(), "tbl_df"))
-
-stopifnot(
-  identical(
-    names(get_charlson_codes()),
-    c("icdv", "dx", "full_code", "code", "condition", "charlson_cdmf2019", "charlson_deyo1992", "charlson_quan2005", "charlson_quan2011")
-  )
-)
-
-stopifnot(
-  identical(
-    sapply(get_charlson_codes(), class),
-    c(icdv = "integer",
-      dx = "integer",
-      full_code = "character",
-      code = "character",
-      condition = "character",
-      charlson_cdmf2019 = "integer",
-      charlson_deyo1992 = "integer",
-      charlson_quan2005 = "integer",
-      charlson_quan2011 = "integer"
-    )
-  )
-)
-
-# check that the row names are just sequential integers
-cc <- get_charlson_codes()
-ci <- get_charlson_index_scores()
-stopifnot(identical(rownames(cc), as.character(seq_len(nrow(cc)))))
-stopifnot(identical(rownames(ci), as.character(seq_len(nrow(ci)))))
-
-################################################################################
-#                                 End of File                                  #
-################################################################################
diff --git a/tests/test-charlson-index-scores.R b/tests/test-charlson-index-scores.R
deleted file mode 100644
index da672be9..00000000
--- a/tests/test-charlson-index-scores.R
+++ /dev/null
@@ -1,35 +0,0 @@
-library(medicalcoder)
-source('utilities.R')
-
-stopifnot(is.data.frame(medicalcoder:::..mdcr_internal_charlson_index_scores..))
-
-stopifnot(
-  identical(
-    names(medicalcoder:::..mdcr_internal_charlson_index_scores..),
-    c("condition_description", "condition", "charlson_cdmf2019", "charlson_quan2011", "charlson_quan2005", "charlson_deyo1992")
-  )
-)
-
-stopifnot(
-  identical(
-    sapply(medicalcoder:::..mdcr_internal_charlson_index_scores.., class),
-    c(condition_description = "character",
-      condition = "character",
-      charlson_cdmf2019 = "integer",
-      charlson_quan2011 = "integer",
-      charlson_quan2005 = "integer",
-      charlson_deyo1992 = "integer"
-    )
-  )
-)
-
-
-stopifnot(is.data.frame(get_charlson_index_scores()))
-
-stopifnot(
-  identical(get_charlson_index_scores(), medicalcoder:::..mdcr_internal_charlson_index_scores..)
-)
-
-################################################################################
-#                                 End of File                                  #
-################################################################################
diff --git a/tests/test-data-frame-tools.R b/tests/test-data-frame-tools.R
new file mode 100644
index 00000000..97c88555
--- /dev/null
+++ b/tests/test-data-frame-tools.R
@@ -0,0 +1,310 @@
+# No need to load and attach the namespace, everything in this test script is
+# non-exported
+# library(medicalcoder)
+source('utilities.R')
+
+dataframetools <-
+  c("mdcr_set",
+    "mdcr_select",
+    "mdcr_subset",
+    "mdcr_setorder",
+    "mdcr_setnames",
+    "mdcr_duplicated"
+  )
+
+mdcr <- getNamespace("medicalcoder")
+
+# are all the dataframetools in the namespcae
+stopifnot(all(dataframetools %in% names(mdcr)))
+
+# check that there are not unaccounted for data sets.  the ..mdcr_internal_
+# prefix and .. suffix is expected.  noted in the data-raw/build_sysdata.R
+stopifnot(
+  all(
+    grep("^mdcr_", names(mdcr), value = TRUE) %in% dataframetools
+  )
+)
+
+################################################################################
+# Set up data for testing
+DF <- data.frame(A = 1:10, C = NA_integer_, B = LETTERS[1:10])
+if (requireNamespace("tibble", quietly = TRUE)) {
+  TBL <- getExportedValue(name = "as_tibble", ns = "tibble")(DF)
+} else {
+  TBL <- DF
+}
+if (requireNamespace("data.table", quietly = TRUE)) {
+  DT <- getExportedValue(name = "copy", ns = "data.table")(DF)
+  getExportedValue(name = "setDT", ns = "data.table")(DT)
+} else {
+  DT <- DF
+}
+
+################################################################################
+# set the value of column C in row 5
+DF  <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(DF,  i = 5L, j = "C", value = 3L)
+TBL <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(TBL, i = 5L, j = "C", value = 3L)
+DT  <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(DT,  i = 5L, j = "C", value = 3L)
+
+stopifnot(
+  identical(DF[["C"]],  c(rep(NA_integer_, 4L), 3L, rep(NA_integer_, 5L))),
+  identical(TBL[["C"]], c(rep(NA_integer_, 4L), 3L, rep(NA_integer_, 5L))),
+  identical(DT[["C"]],  c(rep(NA_integer_, 4L), 3L, rep(NA_integer_, 5L)))
+)
+
+# set the value in two rows at a time with one value
+DF  <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(DF,  i = c(1L, 10L), j = "C", value = 8L)
+TBL <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(TBL, i = c(1L, 10L), j = "C", value = 8L)
+DT  <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(DT,  i = c(1L, 10L), j = "C", value = 8L)
+
+stopifnot(
+  identical(DF[["C"]],  c(8L, rep(NA_integer_, 3L), 3L, rep(NA_integer_, 4L), 8L)),
+  identical(TBL[["C"]], c(8L, rep(NA_integer_, 3L), 3L, rep(NA_integer_, 4L), 8L)),
+  identical(DT[["C"]],  c(8L, rep(NA_integer_, 3L), 3L, rep(NA_integer_, 4L), 8L))
+)
+
+# set the value in three rows at a time with three values
+DF  <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(DF,  i = c(2L, 3L, 4L), j = "C", value = c(21L, 22L, 23L))
+TBL <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(TBL, i = c(2L, 3L, 4L), j = "C", value = c(21L, 22L, 23L))
+DT  <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(DT,  i = c(2L, 3L, 4L), j = "C", value = c(21L, 22L, 23L))
+
+stopifnot(
+  identical(DF[["C"]],  c(8L, 21L, 22L, 23L, 3L, rep(NA_integer_, 4L), 8L)),
+  identical(TBL[["C"]], c(8L, 21L, 22L, 23L, 3L, rep(NA_integer_, 4L), 8L)),
+  identical(DT[["C"]],  c(8L, 21L, 22L, 23L, 3L, rep(NA_integer_, 4L), 8L))
+)
+
+# set a full column
+DF  <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(DF,  j = "A", value = as.integer(11:20))
+TBL <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(TBL, j = "A", value = as.integer(11:20))
+DT  <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(DT,  j = "A", value = as.integer(11:20))
+
+stopifnot(
+  identical(DF[["A"]],  as.integer(11:20)),
+  identical(TBL[["A"]], as.integer(11:20)),
+  identical(DT[["A"]],  as.integer(11:20))
+)
+
+# create a new column
+x <- paste("v", c(0:5, 5, 6:8))
+DF  <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(DF,  j = "D", value = x)
+TBL <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(TBL, j = "D", value = x)
+DT  <- getFromNamespace(x = "mdcr_set", ns = "medicalcoder")(DT,  j = "D", value = x)
+
+stopifnot(
+  identical(DF[["D"]],  x),
+  identical(TBL[["D"]], x),
+  identical(DT[["D"]],  x)
+)
+
+################################################################################
+# testing mdcr_select
+# set colummns - change the order of the columns
+DF  <- getFromNamespace(x = "mdcr_select", ns = "medicalcoder")(DF,  col = c("D", "B", "C", "A"))
+TBL <- getFromNamespace(x = "mdcr_select", ns = "medicalcoder")(TBL, col = c("D", "B", "C", "A"))
+DT  <- getFromNamespace(x = "mdcr_select", ns = "medicalcoder")(DT,  col = c("D", "B", "C", "A"))
+
+stopifnot(
+  identical(names(DF),  c("D", "B", "C", "A")),
+  identical(names(TBL), c("D", "B", "C", "A")),
+  identical(names(DT),  c("D", "B", "C", "A"))
+)
+
+# retun the object if col is missing
+stopifnot(
+  identical(getFromNamespace(x = "mdcr_select", ns = "medicalcoder")(DF), DF),
+  identical(getFromNamespace(x = "mdcr_select", ns = "medicalcoder")(TBL), TBL),
+  identical(getFromNamespace(x = "mdcr_select", ns = "medicalcoder")(DT), DT)
+)
+
+################################################################################
+# testing mdcr_subset
+
+# if arg i and cols are missing then the object is retruned
+stopifnot(
+  identical(getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DF), DF),
+  identical(getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(TBL), TBL),
+  identical(getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DT), DT)
+)
+
+# with no row specfied, it is the same as calling mdcr_select
+stopifnot(
+  identical(
+    getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DF,  col = c("D", "B", "C", "A")),
+    getFromNamespace(x = "mdcr_select", ns = "medicalcoder")(DF,  col = c("D", "B", "C", "A"))
+  ),
+  identical(
+    getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(TBL, col = c("D", "B", "C", "A")),
+    getFromNamespace(x = "mdcr_select", ns = "medicalcoder")(TBL, col = c("D", "B", "C", "A"))
+  ),
+  identical(
+    getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DT,  col = c("D", "B", "C", "A")),
+    getFromNamespace(x = "mdcr_select", ns = "medicalcoder")(DT,  col = c("D", "B", "C", "A"))
+  )
+)
+
+# select one column and a subset of rows
+DF0 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DF, i = seq(1, 10, by = 2), cols = c("B"))
+DF1 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DF, i = seq(2, 10, by = 2), cols = c("B"))
+TBL0 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(TBL, i = seq(1, 10, by = 2), cols = c("B"))
+TBL1 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(TBL, i = seq(2, 10, by = 2), cols = c("B"))
+DT0 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DT, i = seq(1, 10, by = 2), cols = c("B"))
+DT1 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DT, i = seq(2, 10, by = 2), cols = c("B"))
+
+stopifnot(
+  inherits(DF0, "data.frame"),
+  inherits(DF1, "data.frame"),
+  inherits(TBL0, "data.frame"),
+  inherits(TBL1, "data.frame"),
+  inherits(DT0, "data.frame"),
+  inherits(DT1, "data.frame"),
+  identical(names(DF0), "B"),
+  identical(names(DF1), "B"),
+  identical(names(TBL0), "B"),
+  identical(names(TBL1), "B"),
+  identical(names(DT0), "B"),
+  identical(names(DT1), "B")
+)
+
+if (requireNamespace("data.table", quietly = TRUE)) {
+  stopifnot(inherits(DT0, "data.table"), inherits(DT1, "data.table"))
+}
+
+if (requireNamespace("tibble", quietly = TRUE)) {
+  stopifnot(inherits(TBL0, "tbl_df"), inherits(TBL1, "tbl_df"))
+}
+
+# select two columns
+DF0 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DF, i = seq(1, 10, by = 2), cols = c("B", "A"))
+DF1 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DF, i = seq(2, 10, by = 2), cols = c("B", "A"))
+TBL0 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(TBL, i = seq(1, 10, by = 2), cols = c("B", "A"))
+TBL1 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(TBL, i = seq(2, 10, by = 2), cols = c("B", "A"))
+DT0 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DT, i = seq(1, 10, by = 2), cols = c("B", "A"))
+DT1 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DT, i = seq(2, 10, by = 2), cols = c("B", "A"))
+
+stopifnot(
+  inherits(DF0, "data.frame"),
+  inherits(DF1, "data.frame"),
+  inherits(TBL0, "data.frame"),
+  inherits(TBL1, "data.frame"),
+  inherits(DT0, "data.frame"),
+  inherits(DT1, "data.frame"),
+  identical(names(DF0), c("B", "A")),
+  identical(names(DF1), c("B", "A")),
+  identical(names(TBL0), c("B", "A")),
+  identical(names(TBL1), c("B", "A")),
+  identical(names(DT0), c("B", "A")),
+  identical(names(DT1), c("B", "A"))
+)
+
+if (requireNamespace("data.table", quietly = TRUE)) {
+  stopifnot(inherits(DT0, "data.table"), inherits(DT1, "data.table"))
+}
+
+if (requireNamespace("tibble", quietly = TRUE)) {
+  stopifnot(inherits(TBL0, "tbl_df"), inherits(TBL1, "tbl_df"))
+}
+
+# if only i is supplied, all the columns are returned
+DF0 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DF, i = seq(1, 10, by = 2))
+DF1 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DF, i = seq(2, 10, by = 2))
+TBL0 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(TBL, i = seq(1, 10, by = 2))
+TBL1 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(TBL, i = seq(2, 10, by = 2))
+DT0 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DT, i = seq(1, 10, by = 2))
+DT1 <- getFromNamespace(x = "mdcr_subset", ns = "medicalcoder")(DT, i = seq(2, 10, by = 2))
+
+stopifnot(
+  inherits(DF0, "data.frame"),
+  inherits(DF1, "data.frame"),
+  inherits(TBL0, "data.frame"),
+  inherits(TBL1, "data.frame"),
+  inherits(DT0, "data.frame"),
+  inherits(DT1, "data.frame"),
+  identical(names(DF0), c("D", "B", "C", "A")),
+  identical(names(DF1), c("D", "B", "C", "A")),
+  identical(names(TBL0), c("D", "B", "C", "A")),
+  identical(names(TBL1), c("D", "B", "C", "A")),
+  identical(names(DT0), c("D", "B", "C", "A")),
+  identical(names(DT1), c("D", "B", "C", "A"))
+)
+
+if (requireNamespace("data.table", quietly = TRUE)) {
+  stopifnot(inherits(DT0, "data.table"), inherits(DT1, "data.table"))
+}
+
+if (requireNamespace("tibble", quietly = TRUE)) {
+  stopifnot(inherits(TBL0, "tbl_df"), inherits(TBL1, "tbl_df"))
+}
+
+
+################################################################################
+# testing mdcr_setorder
+DF <- rbind(DF0, DF1)
+TBL <- rbind(TBL0, TBL1)
+DT <- rbind(DT0, DT1)
+
+# verify that the data.frames are not currently ordered by "A"
+
+stopifnot(
+  identical(DF[["A"]],  as.integer(c(11, 13, 15, 17, 19, 12, 14, 16, 18, 20))),
+  identical(TBL[["A"]], as.integer(c(11, 13, 15, 17, 19, 12, 14, 16, 18, 20))),
+  identical(DT[["A"]],  as.integer(c(11, 13, 15, 17, 19, 12, 14, 16, 18, 20))),
+  identical(DF[["D"]],  paste("v", c(0, 2, 4, 5, 7, 1, 3, 5, 6, 8))),
+  identical(TBL[["D"]], paste("v", c(0, 2, 4, 5, 7, 1, 3, 5, 6, 8))),
+  identical(DT[["D"]],  paste("v", c(0, 2, 4, 5, 7, 1, 3, 5, 6, 8)))
+)
+
+DF <-  getFromNamespace(x = "mdcr_setorder", ns = "medicalcoder")(DF, by = c("A"))
+TBL <- getFromNamespace(x = "mdcr_setorder", ns = "medicalcoder")(TBL, by = c("A"))
+DT <-  getFromNamespace(x = "mdcr_setorder", ns = "medicalcoder")(DT, by = c("A"))
+
+stopifnot(
+  identical(DF[["A"]],  as.integer(11:20)),
+  identical(TBL[["A"]], as.integer(11:20)),
+  identical(DT[["A"]],  as.integer(11:20)),
+  identical(DF[["D"]],  paste("v", c(0:5, 5, 6:8))),
+  identical(TBL[["D"]], paste("v", c(0:5, 5, 6:8))),
+  identical(DT[["D"]],  paste("v", c(0:5, 5, 6:8)))
+)
+
+################################################################################
+# testing mdcr_setnames
+DF  <- getFromNamespace(x = "mdcr_setnames", ns = "medicalcoder")(DF,  old = "A", new = "Column A")
+TBL <- getFromNamespace(x = "mdcr_setnames", ns = "medicalcoder")(TBL, old = "A", new = "Column A")
+DT  <- getFromNamespace(x = "mdcr_setnames", ns = "medicalcoder")(DT,  old = "A", new = "Column A")
+
+stopifnot(
+  identical(names(DF),  c("D", "B", "C", "Column A")),
+  identical(names(TBL), c("D", "B", "C", "Column A")),
+  identical(names(DT),  c("D", "B", "C", "Column A"))
+)
+
+################################################################################
+# testing mdcr_duplicated
+
+stopifnot(
+  !any(getFromNamespace(x = "mdcr_duplicated", ns = "medicalcoder")(DF)),
+  !any(getFromNamespace(x = "mdcr_duplicated", ns = "medicalcoder")(TBL)),
+  !any(getFromNamespace(x = "mdcr_duplicated", ns = "medicalcoder")(DT))
+)
+
+expected <- rep(FALSE, 10)
+expected[7] <- TRUE
+stopifnot(
+  identical(getFromNamespace(x = "mdcr_duplicated", ns = "medicalcoder")(DF, by = "D"), expected),
+  identical(getFromNamespace(x = "mdcr_duplicated", ns = "medicalcoder")(TBL, by = "D"), expected),
+  identical(getFromNamespace(x = "mdcr_duplicated", ns = "medicalcoder")(DT, by = "D"), expected)
+)
+
+# check fromLast
+expected[6:7] <- !expected[6:7]
+stopifnot(
+  identical(getFromNamespace(x = "mdcr_duplicated", ns = "medicalcoder")(DF, by = "D", fromLast = TRUE), expected),
+  identical(getFromNamespace(x = "mdcr_duplicated", ns = "medicalcoder")(TBL, by = "D", fromLast = TRUE), expected),
+  identical(getFromNamespace(x = "mdcr_duplicated", ns = "medicalcoder")(DT, by = "D", fromLast = TRUE), expected)
+)
+
+
+################################################################################
+#                                 End of File                                  #
+################################################################################
diff --git a/tests/test-elixhauser-codes.R b/tests/test-elixhauser-codes.R
deleted file mode 100644
index 693bf210..00000000
--- a/tests/test-elixhauser-codes.R
+++ /dev/null
@@ -1,96 +0,0 @@
-source('utilities.R')
-library(medicalcoder)
-
-################################################################################
-# test the structure of the internal object
-
-stopifnot(is.data.frame(medicalcoder:::..mdcr_internal_elixhauser_codes..))
-
-stopifnot(
-  identical(
-    names(medicalcoder:::..mdcr_internal_elixhauser_codes..),
-    c("code_id",
-      "poaexempt",
-      "condition",
-      "elixhauser_ahrq_web",
-      "elixhauser_elixhauser1988",
-      "elixhauser_quan2005",
-      "elixhauser_ahrq2022",
-      "elixhauser_ahrq2023",
-      "elixhauser_ahrq2024",
-      "elixhauser_ahrq2025",
-      "elixhauser_ahrq_icd10"
-    )
-  )
-)
-
-stopifnot(
-  identical(
-    sapply(medicalcoder:::..mdcr_internal_elixhauser_codes.., class),
-    c(code_id = "integer",
-      poaexempt = "integer",
-      condition = "character",
-      elixhauser_ahrq_web = "integer",
-      elixhauser_elixhauser1988 = "integer",
-      elixhauser_quan2005 = "integer",
-      elixhauser_ahrq2022 = "integer",
-      elixhauser_ahrq2023 = "integer",
-      elixhauser_ahrq2024 = "integer",
-      elixhauser_ahrq2025 = "integer",
-      elixhauser_ahrq_icd10 = "integer"
-    )
-  )
-)
-
-################################################################################
-# Test the structure of the object returned by get_elixhauser_codes()
-
-stopifnot(is.data.frame(get_elixhauser_codes()))
-
-stopifnot(
-  identical(
-    names(get_elixhauser_codes()),
-    c("icdv", "dx", "full_code", "code",
-      "poaexempt",
-      "condition",
-      "elixhauser_ahrq_web",
-      "elixhauser_elixhauser1988",
-      "elixhauser_quan2005",
-      "elixhauser_ahrq2022",
-      "elixhauser_ahrq2023",
-      "elixhauser_ahrq2024",
-      "elixhauser_ahrq2025",
-      "elixhauser_ahrq_icd10"
-    )
-  )
-)
-
-
-stopifnot(
-  identical(
-    sapply(get_elixhauser_codes(), class),
-    c(icdv = "integer",
-      dx = "integer",
-      full_code = "character",
-      code = "character",
-      poaexempt = "integer",
-      condition = "character",
-      elixhauser_ahrq_web = "integer",
-      elixhauser_elixhauser1988 = "integer",
-      elixhauser_quan2005 = "integer",
-      elixhauser_ahrq2022 = "integer",
-      elixhauser_ahrq2023 = "integer",
-      elixhauser_ahrq2024 = "integer",
-      elixhauser_ahrq2025 = "integer",
-      elixhauser_ahrq_icd10 = "integer"
-    )
-  )
-)
-
-# check that the row names are just sequential integers
-ec <- get_elixhauser_codes()
-stopifnot(identical(rownames(ec), as.character(seq_len(nrow(ec)))))
-
-################################################################################
-#                                 End of File                                  #
-################################################################################
diff --git a/tests/test-elixhauser-example.R b/tests/test-elixhauser-example.R
index dedcc897..866ac4aa 100644
--- a/tests/test-elixhauser-example.R
+++ b/tests/test-elixhauser-example.R
@@ -3,8 +3,7 @@ library(medicalcoder)
 
 ################################################################################
 # Regression test: selected ICD-10 codes should map to specific Elixhauser
-# comorbidities under the Quan (2005) implementation. The codes were drawn from
-# the internal lookup table (get_elixhauser_codes()).
+# comorbidities under the Quan (2005) implementation. 
 ################################################################################
 
 example_codes <-
diff --git a/tests/test-elixhauser-index-scores.R b/tests/test-elixhauser-index-scores.R
deleted file mode 100644
index 4903de4a..00000000
--- a/tests/test-elixhauser-index-scores.R
+++ /dev/null
@@ -1,31 +0,0 @@
-source('utilities.R')
-library(medicalcoder)
-
-stopifnot(is.data.frame(medicalcoder:::..mdcr_internal_elixhauser_index_scores..))
-
-stopifnot(identical(get_elixhauser_index_scores(), medicalcoder:::..mdcr_internal_elixhauser_index_scores..))
-
-stopifnot(
-  identical(
-    sapply(get_elixhauser_index_scores(), class),
-    c(
-      condition                 = "character",
-      index                     = "character",
-      elixhauser_ahrq_web       = "integer",
-      elixhauser_elixhauser1988 = "integer",
-      elixhauser_quan2005       = "integer",
-      elixhauser_ahrq2022       = "integer",
-      elixhauser_ahrq2023       = "integer",
-      elixhauser_ahrq2024       = "integer",
-      elixhauser_ahrq2025       = "integer",
-      elixhauser_ahrq_icd10     = "integer"
-     )
-  )
-)
-
-eis <- get_elixhauser_index_scores()
-stopifnot(identical(rownames(eis), as.character(seq_len(nrow(eis)))))
-
-################################################################################
-#                                 End of File                                  #
-################################################################################
diff --git a/tests/test-elixhauser-poa.R b/tests/test-elixhauser-poa.R
deleted file mode 100644
index 0699a0f9..00000000
--- a/tests/test-elixhauser-poa.R
+++ /dev/null
@@ -1,29 +0,0 @@
-source('utilities.R')
-library(medicalcoder)
-
-stopifnot(is.data.frame(medicalcoder:::..mdcr_internal_elixhauser_poa..))
-
-stopifnot(identical(get_elixhauser_poa(), medicalcoder:::..mdcr_internal_elixhauser_poa..))
-
-stopifnot(
-  identical(
-    sapply(get_elixhauser_poa(), class),
-    c(condition          = "character",
-      poa_required        = "integer",
-      elixhauser_ahrq2022 = "integer",
-      elixhauser_ahrq2023 = "integer",
-      elixhauser_ahrq2024 = "integer",
-      elixhauser_ahrq2025 = "integer",
-      elixhauser_ahrq_icd10 = "integer"
-    )
-  )
-)
-
-
-# check that the row names are just sequential integers
-ep <- get_elixhauser_poa()
-stopifnot(identical(rownames(ep), as.character(seq_len(nrow(ep)))))
-
-################################################################################
-#                                 End of File                                  #
-################################################################################
diff --git a/tests/test-get_icd.R b/tests/test-get_icd.R
deleted file mode 100644
index 670f0890..00000000
--- a/tests/test-get_icd.R
+++ /dev/null
@@ -1,120 +0,0 @@
-source('utilities.R')
-library(medicalcoder)
-
-ICDCODES     <- get_icd_codes()
-ICDDESCS     <- get_icd_codes(with.descriptions = TRUE,  with.hierarchy = FALSE)
-ICDHIER      <- get_icd_codes(with.descriptions = FALSE, with.hierarchy = TRUE)
-ICDDH        <- get_icd_codes(with.descriptions = TRUE,  with.hierarchy = TRUE)
-
-# The way these functions should work is to build the needed user friendly data
-# set from the internal look up tables and save the result in the a package
-# envrionment.  This is done so the initial call may take some time to build the
-# data, subsequent calls will retrive the cached data.  The next four lines
-# verify that the return from the subsequent call is identical to the initial
-# call.
-ICDCODES2    <- get_icd_codes()
-ICDDESCS2    <- get_icd_codes(with.descriptions = TRUE,  with.hierarchy = FALSE)
-ICDHIER2     <- get_icd_codes(with.descriptions = FALSE, with.hierarchy = TRUE)
-ICDDH2       <- get_icd_codes(with.descriptions = TRUE,  with.hierarchy = TRUE)
-
-stopifnot(isTRUE(identical(ICDCODES, ICDCODES2)))
-stopifnot(isTRUE(identical(ICDDESCS, ICDDESCS2)))
-stopifnot(isTRUE(identical(ICDHIER,  ICDHIER2)))
-stopifnot(isTRUE(identical(ICDDH,    ICDDH2)))
-
-# verify that the ICD codes are data.frames, nothing more.
-stopifnot(class(ICDCODES) == "data.frame")
-stopifnot(class(ICDDESCS) == "data.frame")
-stopifnot(class(ICDHIER)  == "data.frame")
-stopifnot(class(ICDDH)    == "data.frame")
-
-# verify that the row names are just integers
-stopifnot(identical(rownames(ICDCODES), as.character(seq_len(nrow(ICDCODES)))))
-stopifnot(identical(rownames(ICDDESCS), as.character(seq_len(nrow(ICDDESCS)))))
-stopifnot(identical(rownames(ICDHIER),  as.character(seq_len(nrow(ICDHIER)))))
-stopifnot(identical(rownames(ICDDH),    as.character(seq_len(nrow(ICDDH)))))
-
-# verify the names are as expected, the order shouldn't matter, but this test
-# will verify the order is as expected too.
-expected_icd_code_columns <- c("icdv", "dx", "full_code", "code", "src", "known_start", "known_end", "assignable_start", "assignable_end")
-expected_icd_desc_columns <- c("desc", "desc_start", "desc_end")
-expected_icd_hier_columns <- c("chapter", "subchapter", "category", "subcategory", "subclassification", "subsubclassification", "extension")
-stopifnot(isTRUE(identical(names(ICDCODES),   expected_icd_code_columns)))
-stopifnot(isTRUE(identical(names(ICDDESCS), c(expected_icd_code_columns, expected_icd_desc_columns))))
-stopifnot(isTRUE(identical(names(ICDHIER),  c(expected_icd_code_columns, expected_icd_hier_columns))))
-stopifnot(isTRUE(identical(names(ICDDH),    c(expected_icd_code_columns, expected_icd_desc_columns, expected_icd_hier_columns))))
-
-# Verify the column classes are as expected
-nc <-
-  c(
-    "icdv" = "integer",
-    "dx" = "integer",
-    "full_code" = "character",
-    "code" = "character",
-    "src" = "character",
-    "known_start" = "integer",
-    "known_end" = "integer",
-    "assignable_start" = "integer",
-    "assignable_end" = "integer",
-    "desc" = "character",
-    "desc_start" = "integer",
-    "desc_end" = "integer",
-    "chapter" = "character",
-    "subchapter" = "character",
-    "category" = "character",
-    "subcategory" = "character",
-    "subclassification" = "character",
-    "subsubclassification" = "character",
-    "extension" = "character"
-  )
-
-for(j in names(ICDCODES)) {
-  stopifnot(isTRUE(inherits(ICDCODES[[j]], nc[j])))
-}
-
-for(j in names(ICDDESCS)) {
-  stopifnot(isTRUE(inherits(ICDDESCS[[j]], nc[j])))
-}
-
-for(j in names(ICDHIER)) {
-  stopifnot(isTRUE(inherits(ICDHIER[[j]], nc[j])))
-}
-
-for(j in names(ICDDH)) {
-  stopifnot(isTRUE(inherits(ICDDH[[j]], nc[j])))
-}
-
-# if assignable_start is NA then assignable_end should be NA
-idx <- which(is.na(ICDCODES[["assignable_start"]]))
-stopifnot(all(is.na(ICDCODES[["assignable_end"]][idx])))
-
-idx <- which(is.na(ICDHIER[["assignable_start"]]))
-stopifnot(all(is.na(ICDHIER[["assignable_end"]][idx])))
-
-# Verify that columns are populated
-stopifnot(all(Negate(is.na)(ICDCODES[["icdv"]])))
-stopifnot(all(Negate(is.na)(ICDCODES[["dx"]])))
-stopifnot(all(Negate(is.na)(ICDCODES[["full_code"]])))
-stopifnot(all(Negate(is.na)(ICDCODES[["code"]])))
-stopifnot(all(Negate(is.na)(ICDCODES[["known_start"]])))
-stopifnot(all(Negate(is.na)(ICDCODES[["known_end"]])))
-
-stopifnot(all(Negate(is.na)(ICDHIER[["icdv"]])))
-stopifnot(all(Negate(is.na)(ICDHIER[["dx"]])))
-stopifnot(all(Negate(is.na)(ICDHIER[["full_code"]])))
-stopifnot(all(Negate(is.na)(ICDHIER[["code"]])))
-stopifnot(all(Negate(is.na)(ICDHIER[["chapter"]])))
-stopifnot(all(Negate(is.na)(ICDHIER[["known_start"]])))
-stopifnot(all(Negate(is.na)(ICDHIER[["known_end"]])))
-
-# Verify that the src column is as expected
-stopifnot(
-  identical(c("cdc", "cms", "who"), sort(unique(ICDCODES[["src"]]))),
-  identical(c("cdc", "cms", "who"), sort(unique(ICDDESCS[["src"]]))),
-  identical(c("cdc", "cms", "who"), sort(unique(ICDHIER[["src"]]))),
-  identical(c("cdc", "cms", "who"), sort(unique(ICDDH[["src"]])))
-)
-
-################################################################################
-#                                 End of File                                  #
-################################################################################
diff --git a/tests/test-icd-codes.R b/tests/test-icd-codes.R
deleted file mode 100644
index 1d7a2ff2..00000000
--- a/tests/test-icd-codes.R
+++ /dev/null
@@ -1,33 +0,0 @@
-source('utilities.R')
-library(medicalcoder)
-
-################################################################################
-# check the internal data set
-stopifnot(is.data.frame(medicalcoder:::..mdcr_internal_icd_codes..))
-
-stopifnot(
-  identical(
-    names(medicalcoder:::..mdcr_internal_icd_codes..),
-    c("icdv", "dx", "full_code", "code", "code_id", "chap_id", "subchap_id")
-  )
-)
-
-stopifnot(
-  identical(
-    sapply(medicalcoder:::..mdcr_internal_icd_codes.., class),
-    c(icdv = "integer",
-      dx = "integer",
-      full_code = "character",
-      code = "character",
-      code_id = "integer",
-      chap_id = "integer",
-      subchap_id = "integer")
-  )
-)
-
-# see test-get_icd.R
-
-
-################################################################################
-#                                 End of File                                  #
-################################################################################
diff --git a/tests/test-internal-data.R b/tests/test-internal-data.R
new file mode 100644
index 00000000..43393233
--- /dev/null
+++ b/tests/test-internal-data.R
@@ -0,0 +1,250 @@
+library(medicalcoder)
+source("utilities.R")
+################################################################################
+# testing the internal data sets - both the internal sets and the user visible
+# versions.
+
+# The internal sets can to look for: this cannot be done dynamically
+# e <- new.env()
+# load("../R/sysdata.rda", envir = e)
+# dput(sort(ls(all.names = TRUE, envir = e)))
+
+internal_data_sets <-
+  c(
+    "..mdcr_internal_charlson_codes..",
+    "..mdcr_internal_charlson_index_scores..",
+    "..mdcr_internal_desc_start_stop..",
+    "..mdcr_internal_elixhauser_codes..",
+    "..mdcr_internal_elixhauser_index_scores..",
+    "..mdcr_internal_elixhauser_poa..",
+    "..mdcr_internal_icd_chapters..",
+    "..mdcr_internal_icd_codes..",
+    "..mdcr_internal_icd_descs..",
+    "..mdcr_internal_icd_subchapters..",
+    "..mdcr_internal_known_and_assignable_start_stop..",
+    "..mdcr_internal_pccc_codes..",
+    "..mdcr_internal_pccc_conditions.."
+  )
+
+mdcr <- getNamespace("medicalcoder")
+
+# are all the expected sets in the medicalcoder namespace?
+stopifnot(all(internal_data_sets %in% names(mdcr)))
+
+# check that there are not unaccounted for data sets.  the ..mdcr_internal_
+# prefix and .. suffix is expected.  noted in the data-raw/build_sysdata.R
+stopifnot(
+  all(
+    grep("\\.\\.mdcr_internal_.+\\.\\.$", names(mdcr), value = TRUE) %in% internal_data_sets
+  )
+)
+
+################################################################################
+# verify all the sets are data.frames and only data.frames
+t01 <-  all(sapply(sapply(internal_data_sets, get, envir = mdcr), inherits, "data.frame"))
+t02 <- !any(sapply(sapply(internal_data_sets, get, envir = mdcr), inherits, "data.table"))
+t03 <- !any(sapply(sapply(internal_data_sets, get, envir = mdcr), inherits, "tbl_df"))
+
+stopifnot(t01, t02, t03)
+
+################################################################################
+# Verify the names and classes of the internal data sets
+expected_internal_names_and_classes <-
+  list(
+    "..mdcr_internal_charlson_codes.." = c(code_id = "integer", condition = "character", charlson_cdmf2019 = "integer", charlson_deyo1992 = "integer", charlson_quan2005 = "integer", charlson_quan2011 = "integer"),
+    "..mdcr_internal_charlson_index_scores.." = c(condition_description = "character", condition = "character", charlson_cdmf2019 = "integer", charlson_quan2011 = "integer", charlson_quan2005 = "integer", charlson_deyo1992 = "integer"),
+    "..mdcr_internal_desc_start_stop.." = c(code_id = "integer", desc_id = "integer", src = "factor", desc_start = "integer", desc_end = "integer"),
+    "..mdcr_internal_elixhauser_codes.." = c(code_id = "integer", poaexempt = "integer", condition = "character", elixhauser_ahrq_web = "integer", elixhauser_elixhauser1988 = "integer", elixhauser_quan2005 = "integer", elixhauser_ahrq2022 = "integer", elixhauser_ahrq2023 = "integer", elixhauser_ahrq2024 = "integer", elixhauser_ahrq2025 = "integer", elixhauser_ahrq_icd10 = "integer"),
+    "..mdcr_internal_elixhauser_index_scores.." = c(condition = "character", index = "character", elixhauser_ahrq_web = "integer", elixhauser_elixhauser1988 = "integer", elixhauser_quan2005 = "integer", elixhauser_ahrq2022 = "integer", elixhauser_ahrq2023 = "integer", elixhauser_ahrq2024 = "integer", elixhauser_ahrq2025 = "integer", elixhauser_ahrq_icd10 = "integer"),
+    "..mdcr_internal_elixhauser_poa.." = c(condition = "character", poa_required = "integer", elixhauser_ahrq2022 = "integer", elixhauser_ahrq2023 = "integer", elixhauser_ahrq2024 = "integer", elixhauser_ahrq2025 = "integer", elixhauser_ahrq_icd10 = "integer"),
+    "..mdcr_internal_icd_chapters.." = c(chapter = "character", chap_id = "integer"),
+    "..mdcr_internal_icd_codes.." = c(icdv = "integer", dx = "integer", full_code = "character", code = "character", code_id = "integer", chap_id = "integer", subchap_id = "integer"),
+    "..mdcr_internal_icd_descs.." = c(desc = "character", desc_id = "integer"),
+    "..mdcr_internal_icd_subchapters.." = c(subchapter = "character", subchap_id = "integer"),
+    "..mdcr_internal_known_and_assignable_start_stop.." = c(code_id = "integer", src = "factor", known_start = "integer", known_end = "integer", assignable_start = "integer", assignable_end = "integer"),
+    "..mdcr_internal_pccc_codes.." = c(code_id = "integer", condition = "character", subcondition = "character", transplant_flag = "integer", tech_dep_flag = "integer", pccc_v3.1 = "integer", pccc_v3.0 = "integer", pccc_v2.1 = "integer", pccc_v2.0 = "integer"),
+    "..mdcr_internal_pccc_conditions.." = c(condition = "character", subcondition = "character", condition_label = "character", subcondition_label = "character")
+  )
+
+current_names_and_classes <- sapply(sapply(internal_data_sets, get, envir = mdcr), sapply, class)
+
+stopifnot(identical(length(current_names_and_classes), length(expected_internal_names_and_classes)))
+
+for(n in names(current_names_and_classes)) {
+  z <- identical(current_names_and_classes[[n]], expected_internal_names_and_classes[[n]])
+  if (!z) {
+    stop(sprintf("user visible %s does not have the expected structure", n))
+  }
+}
+
+#for (n in names(current_names)) {
+#  if (!identical(names(get(n, envir = mdcr)), expected_names[[n]])) {
+#    stop(sprintf("names(%s) are not as expected", n))
+#  }
+#}
+
+
+################################################################################
+# get the data sets via get_ methods
+
+# expected methods
+user_visible_get_methods <-
+  c(
+    "get_charlson_codes",
+    "get_charlson_index_scores",
+    "get_elixhauser_codes",
+    "get_elixhauser_index_scores",
+    "get_elixhauser_poa",
+    "get_icd_codes",
+    "get_pccc_codes",
+    "get_pccc_conditions"
+  )
+
+# check that the expected methods are accounted for
+stopifnot(all(user_visible_get_methods %in% names(mdcr)))
+stopifnot(all(grep("get_.+", names(mdcr), value = TRUE) %in% user_visible_get_methods))
+
+# all the get_* methods have zero arguments except for get_icd_codes
+for (m in user_visible_get_methods) {
+  f <- getExportedValue(name = m, ns = "medicalcoder")
+  x <- formals(f)
+  if (m != "get_icd_codes") {
+    if (!is.null(x)) {
+      stop(sprintf("Unexpected function argument in %s()", m))
+    }
+  } else {
+    if (!identical(x, pairlist(with.descriptions = FALSE, with.hierarchy = FALSE))) {
+      stop(sprintf("Unexpected function argument in %s()", m))
+    }
+  }
+}
+
+# get the datasets
+user_visible <-
+  list(
+    charlson_codes = get_charlson_codes(),
+    charlson_index_scores = get_charlson_index_scores(),
+    elixhauser_codes = get_elixhauser_codes(),
+    elixhauser_index_scores = get_elixhauser_index_scores(),
+    elixhauser_poa = get_elixhauser_poa(),
+    icd_codes = get_icd_codes(),
+    icd_desc = get_icd_codes(with.descriptions = TRUE),
+    icd_hier = get_icd_codes(with.hierarchy = TRUE),
+    icd_dh   = get_icd_codes(with.descriptions = TRUE, with.hierarchy = TRUE),
+    pccc_codes = get_pccc_codes(),
+    pccc_conditions = get_pccc_conditions()
+  )
+
+# verify all the sets are data.frames and only data.frames
+t04 <-  all(sapply(user_visible, inherits, "data.frame"))
+t05 <- !any(sapply(user_visible, inherits, "data.table"))
+t06 <- !any(sapply(user_visible, inherits, "tbl_df"))
+
+stopifnot(t04, t05, t06)
+
+# define the expected structure
+user_visible_expected_structures <-
+  list(
+    charlson_codes = c(icdv = "integer", dx = "integer", full_code = "character", code = "character", condition = "character", charlson_cdmf2019 = "integer", charlson_deyo1992 = "integer", charlson_quan2005 = "integer", charlson_quan2011 = "integer"),
+    charlson_index_scores = expected_internal_names_and_classes$..mdcr_internal_charlson_index_scores..,
+    elixhauser_codes = c(icdv = "integer", dx = "integer", full_code = "character", code = "character", poaexempt = "integer", condition = "character", elixhauser_ahrq_web = "integer", elixhauser_elixhauser1988 = "integer", elixhauser_quan2005 = "integer", elixhauser_ahrq2022 = "integer", elixhauser_ahrq2023 = "integer", elixhauser_ahrq2024 = "integer", elixhauser_ahrq2025 = "integer", elixhauser_ahrq_icd10 = "integer"),
+    elixhauser_index_scores = expected_internal_names_and_classes$..mdcr_internal_elixhauser_index_scores..,
+    elixhauser_poa = expected_internal_names_and_classes$..mdcr_internal_elixhauser_poa..,
+    icd_codes = c(icdv = "integer", dx = "integer", full_code = "character", code = "character", src = "character", known_start = "integer", known_end = "integer", assignable_start = "integer", assignable_end = "integer"),
+    icd_desc = c(icdv = "integer", dx = "integer", full_code = "character", code = "character", src = "character", known_start = "integer", known_end = "integer", assignable_start = "integer", assignable_end = "integer", desc = "character", desc_start = "integer", desc_end = "integer"),
+    icd_hier = c(icdv = "integer", dx = "integer", full_code = "character", code = "character", src = "character", known_start = "integer", known_end = "integer", assignable_start = "integer", assignable_end = "integer", chapter = "character", subchapter = "character", category = "character", subcategory = "character", subclassification = "character", subsubclassification = "character", extension = "character"),
+    icd_dh = c(icdv = "integer", dx = "integer", full_code = "character", code = "character", src = "character", known_start = "integer", known_end = "integer", assignable_start = "integer", assignable_end = "integer", desc = "character", desc_start = "integer", desc_end = "integer", chapter = "character", subchapter = "character", category = "character", subcategory = "character", subclassification = "character", subsubclassification = "character", extension = "character"),
+    pccc_codes = c(icdv = "integer", dx = "integer", full_code = "character", code = "character", condition = "character", subcondition = "character", transplant_flag = "integer", tech_dep_flag = "integer", pccc_v3.1 = "integer", pccc_v3.0 = "integer", pccc_v2.1 = "integer", pccc_v2.0 = "integer"),
+    pccc_conditions = expected_internal_names_and_classes$..mdcr_internal_pccc_conditions..
+  )
+
+user_visible_current_structures <- lapply(user_visible, sapply, class)
+
+for(n in names(user_visible_current_structures)) {
+  z <- identical(user_visible_current_structures[[n]], user_visible_expected_structures[[n]])
+  if (!z) {
+    stop(sprintf("user visible %s does not have the expected structure", n))
+  }
+}
+
+# check that the row names are just sequential integers
+for (n in names(user_visible)) {
+  expected <- as.character(seq_len(nrow(user_visible[[n]])))
+  current  <- rownames(user_visible[[n]])
+  if (!identical(expected, current)) {
+    stop(sprintf("rownames(user_visible[[%s]]) are not sequential integers", n))
+  }
+}
+
+################################################################################
+# verify *_codes are all valid codes
+for (n in grep("_codes$", names(user_visible), value = TRUE)) {
+  z <- is_icd(x = user_visible[[n]][["code"]],
+    icdv = user_visible[[n]][["icdv"]],
+    dx   = user_visible[[n]][["dx"]],
+    headerok = TRUE,
+    ever.assignable = TRUE,
+    warn.ambiguous = FALSE
+  )
+  if (!all(z)) {
+    stop(sprintf("not all user_visible[['%s']][['code']] are valid ever.assignable ICD codes", n))
+  }
+  z <- is_icd(x = user_visible[[n]][["full_code"]],
+    icdv = user_visible[[n]][["icdv"]],
+    dx   = user_visible[[n]][["dx"]],
+    headerok = TRUE,
+    ever.assignable = TRUE,
+    warn.ambiguous = FALSE
+  )
+  if (!all(z)) {
+    stop(sprintf("not all user_visible[['%s']][['full_code']] are valid ever.assignable ICD codes", n))
+  }
+}
+################################################################################
+# PCCC specific checks
+#
+# * verify no more than two rows for a code by pccc variant
+variants <- grep("^pccc_", names(user_visible[["pccc_codes"]]), value = TRUE)
+ns <-
+  stats::aggregate(
+    x = user_visible[["pccc_codes"]][variants],
+    by = user_visible[["pccc_codes"]][c("icdv", "dx", "code")],
+    FUN = sum
+  )
+stopifnot(unlist(ns[variants]) %in% c(0L, 1L, 2L))
+
+################################################################################
+# ICD code specific checks
+
+# assignable_start is NA then assignable_end should be NA
+for (n in grep("^icd_", names(user_visible), value = TRUE)) {
+  x <- is.na(user_visible[[n]][["assignable_start"]])
+  y <- is.na(user_visible[[n]][["assignable_end"]])
+  z <- identical(x, y)
+  if (!z) {
+    stop(sprintf("is.na status of assignable_start and assignable_end are not identical for %s", n))
+  }
+}
+
+# verify that columns which are expected to be fully populated are
+for (n in grep("^icd_", names(user_visible), value = TRUE)) {
+  for (j in c("icdv", "dx", "full_code", "code", "known_start", "known_end", "src")) {
+    z <- all(Negate(is.na)(user_visible[[n]][[j]]))
+    if (!z) {
+      stop(sprintf("user_visible[['%s']][['%s']] has missing values", n, j))
+    }
+  }
+}
+
+# Verify that the src column is as expected
+for (n in grep("^icd_", names(user_visible), value = TRUE)) {
+  stopifnot(
+    identical(c("cdc", "cms", "who"), sort(unique(user_visible[[n]][["src"]])))
+  )
+}
+
+
+
+################################################################################
+#                                 End of File                                  #
+################################################################################
diff --git a/tests/test-longitudinal-pccc-v3.1.R b/tests/test-longitudinal-pccc-v3.1.R
index f12a3d0f..4bb65da7 100644
--- a/tests/test-longitudinal-pccc-v3.1.R
+++ b/tests/test-longitudinal-pccc-v3.1.R
@@ -8,8 +8,12 @@ codes <-
     "J84.111", # respiratory (chronic respiratory disease)
     "Z96.41"   # metabolic (device and technology use)
   )
-subset(get_pccc_codes(), full_code %in% codes)
 
+# verify that these codes are as expected
+x <- subset(get_pccc_codes(), full_code %in% codes)
+rownames(x) <- NULL
+expected <- structure(list(icdv = c(10L, 10L, 10L), dx = c(1L, 1L, 1L), full_code = c("H49.811", "J84.111", "Z96.41"), code = c("H49811", "J84111", "Z9641"), condition = c("metabolic", "respiratory", "metabolic"), subcondition = c("other_metabolic_disorders", "chronic_respiratory_diseases", "device_and_technology_use"), transplant_flag = c(0L, 0L, 0L), tech_dep_flag = c(0L, 0L, 1L), pccc_v3.1 = c(1L, 1L, 1L), pccc_v3.0 = c(1L, 1L, 1L), pccc_v2.1 = c(1L, 0L, 1L), pccc_v2.0 = c(1L, 0L, 1L)), row.names = c(NA, -3L), class = "data.frame")
+stopifnot(identical(x, expected))
 
 # build six permutations of these codes.  The codes will be considered poa on
 # encounters 2, 4, and 6.  There will be seven encounters for each permutation.
diff --git a/tests/test-lookup_icd_codes.R b/tests/test-lookup_icd_codes.R
index 08d4ba9b..a74a6a20 100644
--- a/tests/test-lookup_icd_codes.R
+++ b/tests/test-lookup_icd_codes.R
@@ -3,11 +3,15 @@ library(medicalcoder)
 
 # lookup exact vs regex consistency
 lx <- lookup_icd_codes(c("E11.9","I50.9"), regex = FALSE)
+lf <- lookup_icd_codes(factor(c("E11.9","I50.9")), regex = FALSE)
 lr <- lookup_icd_codes(c("^E11\\.9$","^I50\\.9$"), regex = TRUE)
-stopifnot(all(lx$full_code %in% lr$full_code),
-          all(lr$full_code %in% lx$full_code))
+stopifnot(
+  identical(lx, lf),
+  all(lx$full_code %in% lr$full_code),
+  all(lr$full_code %in% lx$full_code)
+)
 
-# the following used to give an error:
+# the following gives an error:
 #   Error in merge.data.frame(x = input, y = matches, all.x = TRUE, by = c(ifelse(regex,  :
 #     negative length vectors are not allowed
 m <- tryCatchError(lookup_icd_codes(x = "", regex = TRUE))
@@ -31,6 +35,49 @@ stopifnot(
   identical(names(m4), expected_regex_true_names)
 )
 
+################################################################################
+# tests for matching by full and/or compact codes
+
+# without regex
+x00 <- tryCatchError(lookup_icd_codes(x = c("E000", "E000.0"), full.codes = FALSE, compact.codes = FALSE))
+stopifnot(inherits(x00, "error"))
+
+# The fallowing tests may fail when ICD codes are updated.  As of 17 Nov 2025,
+# there are codes with known end and assignable_end of 2026
+x01 <- lookup_icd_codes(x = c("E000", "E000.0"), full.codes = FALSE, compact.codes = TRUE)
+x10 <- lookup_icd_codes(x = c("E000", "E000.0"), full.codes = TRUE, compact.codes = FALSE)
+x11 <- lookup_icd_codes(x = c("E000", "E000.0"), full.codes = TRUE, compact.codes = TRUE)
+
+e01 <- structure(list(input_code = c("E000", "E000", "E000", "E000", "E000.0"), match_type = c("compact_code", "compact_code", "compact_code", "compact_code", NA), icdv = c(10L, 9L, 10L, 10L, NA), dx = c(1L, 1L, 1L, 1L, NA), full_code = c("E00.0", "E000", "E00.0", "E00.0", NA), code = c("E000", "E000", "E000", "E000", NA), src = c("cms", "cms", "who", "cdc", NA), known_start = c(2014L, 2010L, 2008L, 2001L, NA), known_end = c(2026L, 2015L, 2019L, 2025L, NA), assignable_start = c(2014L, NA, 2008L, 2001L, NA), assignable_end = c(2026L, NA, 2019L, 2025L, NA)), row.names = c(NA, 5L), class = "data.frame")
+e10 <- structure(list(input_code = c("E000", "E000.0"), match_type = c("full_code", "full_code"), icdv = c(9L, 9L), dx = c(1L, 1L), full_code = c("E000", "E000.0"), code = c("E000", "E0000"), src = c("cms", "cms"), known_start = c(2010L, 2010L), known_end = c(2015L, 2015L), assignable_start = c(NA, 2010L), assignable_end = c(NA, 2015L)), row.names = 1:2, class = "data.frame")
+e11 <- structure(list(input_code = c("E000", "E000", "E000", "E000", "E000.0"), match_type = c("full_code", "compact_code", "compact_code", "compact_code", "full_code"), icdv = c(9L, 10L, 10L, 10L, 9L), dx = c(1L, 1L, 1L, 1L, 1L), full_code = c("E000", "E00.0", "E00.0", "E00.0", "E000.0"), code = c("E000", "E000", "E000", "E000", "E0000"), src = c("cms", "cms", "who", "cdc", "cms"), known_start = c(2010L, 2014L, 2008L, 2001L, 2010L), known_end = c(2015L, 2026L, 2019L, 2025L, 2015L), assignable_start = c(NA, 2014L, 2008L, 2001L, 2010L), assignable_end = c(NA, 2026L, 2019L, 2025L, 2015L)), row.names = c(NA, 5L), class = "data.frame")
+
+stopifnot(
+  identical(x01, e01),
+  identical(x10, e10),
+  identical(x11, e11)
+)
+
+# with regex
+x00 <- tryCatchError(lookup_icd_codes(x = c("E000", "E000\\.0"), regex = TRUE, full.codes = FALSE, compact.codes = FALSE))
+stopifnot(inherits(x00, "error"))
+
+# The fallowing tests may fail when ICD codes are updated.  As of 17 Nov 2025,
+# there are codes with known end and assignable_end of 2026
+x01 <- lookup_icd_codes(x = c("E000", "E000\\.0"), regex = TRUE, full.codes = FALSE, compact.codes = TRUE)
+x10 <- lookup_icd_codes(x = c("E000", "E000\\.0"), regex = TRUE, full.codes = TRUE, compact.codes = FALSE)
+x11 <- lookup_icd_codes(x = c("E000", "E000\\.0"), regex = TRUE, full.codes = TRUE, compact.codes = TRUE)
+
+e01 <- structure(list(input_regex = c("E000", "E000", "E000", "E000", "E000", "E000", "E000", "E000", "E000"), match_type = c("compact_code", "compact_code", "compact_code", "compact_code", "compact_code", "compact_code", "compact_code", "compact_code", "compact_code"), icdv = c(10L, 10L, 9L, 10L, 9L, 9L, 9L, 9L, 9L), dx = c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), full_code = c("E00.0", "E00.0", "E000", "E00.0", "E000.0", "E000.1", "E000.2", "E000.8", "E000.9"), code = c("E000", "E000", "E000", "E000", "E0000", "E0001", "E0002", "E0008", "E0009"), src = c("who", "cms", "cms", "cdc", "cms", "cms", "cms", "cms", "cms"), known_start = c(2008L, 2014L, 2010L, 2001L, 2010L, 2010L, 2011L, 2010L, 2010L), known_end = c(2019L, 2026L, 2015L, 2025L, 2015L, 2015L, 2015L, 2015L, 2015L), assignable_start = c(2008L, 2014L, NA, 2001L, 2010L, 2010L, 2011L, 2010L, 2010L), assignable_end = c(2019L, 2026L, NA, 2025L, 2015L, 2015L, 2015L, 2015L, 2015L)), row.names = c(1L, 2L, 3L, 4L, 17L, 18L, 19L, 20L, 21L), class = "data.frame")
+e10 <- structure(list(input_regex = c("E000", "E000", "E000", "E000", "E000", "E000", "E000\\.0"), match_type = c("full_code", "full_code", "full_code", "full_code", "full_code", "full_code", "full_code"), icdv = c(9L, 9L, 9L, 9L, 9L, 9L, 9L), dx = c(1L, 1L, 1L, 1L, 1L, 1L, 1L), full_code = c("E000", "E000.0", "E000.1", "E000.2", "E000.8", "E000.9", "E000.0"), code = c("E000", "E0000", "E0001", "E0002", "E0008", "E0009", "E0000"), src = c("cms", "cms", "cms", "cms", "cms", "cms", "cms"), known_start = c(2010L, 2010L, 2010L, 2011L, 2010L, 2010L, 2010L), known_end = c(2015L, 2015L, 2015L, 2015L, 2015L, 2015L, 2015L), assignable_start = c(NA, 2010L, 2010L, 2011L, 2010L, 2010L, 2010L), assignable_end = c(NA, 2015L, 2015L, 2015L, 2015L, 2015L, 2015L)), row.names = c(1L, 2L, 3L, 4L, 5L, 6L, 37L), class = "data.frame")
+e11 <- structure(list(input_regex = c("E000", "E000", "E000", "E000", "E000", "E000", "E000", "E000", "E000", "E000", "E000", "E000", "E000", "E000", "E000\\.0"), match_type = c("full_code", "full_code", "full_code", "full_code", "full_code", "full_code", "compact_code", "compact_code", "compact_code", "compact_code", "compact_code", "compact_code", "compact_code", "compact_code", "full_code"), icdv = c(9L, 9L, 9L, 9L, 9L, 9L, 10L, 10L, 10L, 9L, 9L, 9L, 9L, 9L, 9L), dx = c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), full_code = c("E000", "E000.0", "E000.9", "E000.1", "E000.2", "E000.8", "E00.0", "E00.0", "E00.0", "E000.0", "E000.9", "E000.1", "E000.2", "E000.8", "E000.0"), code = c("E000", "E0000", "E0009", "E0001", "E0002", "E0008", "E000", "E000", "E000", "E0000", "E0009", "E0001", "E0002", "E0008", "E0000"), src = c("cms", "cms", "cms", "cms", "cms", "cms", "who", "cms", "cdc", "cms", "cms", "cms", "cms", "cms", "cms"), known_start = c(2010L, 2010L, 2010L, 2010L, 2011L, 2010L, 2008L, 2014L, 2001L, 2010L, 2010L, 2010L, 2011L, 2010L, 2010L), known_end = c(2015L, 2015L, 2015L, 2015L, 2015L, 2015L, 2019L, 2026L, 2025L, 2015L, 2015L, 2015L, 2015L, 2015L, 2015L), assignable_start = c(NA, 2010L, 2010L, 2010L, 2011L, 2010L, 2008L, 2014L, 2001L, 2010L, 2010L, 2010L, 2011L, 2010L, 2010L), assignable_end = c(NA, 2015L, 2015L, 2015L, 2015L, 2015L, 2019L, 2026L, 2025L, 2015L, 2015L, 2015L, 2015L, 2015L, 2015L)), row.names = c(1L, 6L, 7L, 8L, 9L, 10L, 11L, 13L, 14L, 23L, 27L, 28L, 29L, 30L, 451L), class = "data.frame")
+
+stopifnot(
+  identical(x01, e01),
+  identical(x10, e10),
+  identical(x11, e11)
+)
+
 ################################################################################
 #                                 End of File                                  #
 ################################################################################
diff --git a/tests/test-pccc-codes.R b/tests/test-pccc-codes.R
deleted file mode 100644
index 18dfc5f0..00000000
--- a/tests/test-pccc-codes.R
+++ /dev/null
@@ -1,87 +0,0 @@
-source('utilities.R')
-library(medicalcoder)
-################################################################################
-# check the internal data set
-stopifnot(is.data.frame(medicalcoder:::..mdcr_internal_pccc_codes..))
-
-stopifnot(
-  identical(
-    names(medicalcoder:::..mdcr_internal_pccc_codes..),
-    c("code_id", "condition", "subcondition", "transplant_flag",
-      "tech_dep_flag", "pccc_v3.1", "pccc_v3.0", "pccc_v2.1", "pccc_v2.0")
-  )
-)
-
-stopifnot(
-  identical(
-    sapply(medicalcoder:::..mdcr_internal_pccc_codes.., class),
-    c(code_id = "integer",
-      condition = "character",
-      subcondition = "character",
-      transplant_flag = "integer",
-      tech_dep_flag = "integer",
-      pccc_v3.1 = "integer",
-      pccc_v3.0 = "integer",
-      pccc_v2.1 = "integer",
-      pccc_v2.0 = "integer"
-    )
-  )
-)
-
-################################################################################
-# Verify that the pccc codes are retrievable as a data.frame
-pccc_codes <- get_pccc_codes()
-
-stopifnot("pccc_codes are a data.frame" = identical(class(pccc_codes), "data.frame"))
-stopifnot(
-  identical(
-    names(pccc_codes),
-    c("icdv", "dx", "full_code", "code", "condition", "subcondition", "transplant_flag", "tech_dep_flag", "pccc_v3.1", "pccc_v3.0", "pccc_v2.1", "pccc_v2.0")
-  )
-)
-
-################################################################################
-# Verify that all the ICD codes in the data set are valid codes
-x <- is_icd(pccc_codes$code, headerok = TRUE, ever.assignable = TRUE, warn.ambiguous = FALSE)
-stopifnot("all compact pccc_codes are valid ever.assignable icd codes" = all(x))
-
-x <- is_icd(pccc_codes$full_code, headerok = TRUE, ever.assignable = TRUE, warn.ambiguous = FALSE)
-stopifnot("all full pccc_codes are valid ever.assignable icd codes" = all(x))
-
-x <- pccc_codes[pccc_codes$icdv == 9 & pccc_codes$dx == 1, "full_code"]
-x <- is_icd(x = x, icdv = 9, dx = 1, headerok = TRUE, ever.assignable = TRUE, warn.ambiguous = FALSE)
-stopifnot("all icdv 9 dx full codes are valid ever.assignable icd codes" = all(x))
-
-x <- pccc_codes[pccc_codes$icdv == 9 & pccc_codes$dx == 0, "full_code"]
-x <- is_icd(x = x, icdv = 9, dx = 0, headerok = TRUE, ever.assignable = TRUE, warn.ambiguous = FALSE)
-stopifnot("all icdv 9 pr full codes are valid ever.assignable icd codes" = all(x))
-
-x <- pccc_codes[pccc_codes$icdv == 10 & pccc_codes$dx == 1, "full_code"]
-x <- is_icd(x = x, icdv = 10, dx = 1L, headerok = TRUE, ever.assignable = TRUE, warn.ambiguous = FALSE)
-stopifnot("all icdv 10 dx full codes are valid ever.assignable icd codes" = all(x))
-
-x <- pccc_codes[pccc_codes$icdv == 10 & pccc_codes$dx == 0L, "full_code"]
-x <- is_icd(x = x, icdv = 10, dx = 0L, headerok = TRUE, ever.assignable = TRUE)
-stopifnot("all icdv 10 pr full codes are valid ever.assignable icd codes" = all(x))
-
-################################################################################
-# verify no more than two rows for a code by pccc variant
-variants <- grep("^pccc_", names(pccc_codes), value = TRUE)
-codes <-
-  aggregate(
-    pccc_codes[variants],
-    by = pccc_codes[c("icdv", "dx", "code")],
-    FUN = sum
-  )
-stopifnot(
-  max(unlist(codes[variants])) == 2
-)
-
-################################################################################
-# check that the row names are just sequential integers
-pc <- get_pccc_codes()
-stopifnot(identical(rownames(pc), as.character(seq_len(nrow(pc)))))
-
-################################################################################
-#                                 End of File                                  #
-################################################################################
diff --git a/tests/test-pccc-conditions.R b/tests/test-pccc-conditions.R
deleted file mode 100644
index 5ae0cf4a..00000000
--- a/tests/test-pccc-conditions.R
+++ /dev/null
@@ -1,28 +0,0 @@
-source('utilities.R')
-library(medicalcoder)
-
-stopifnot(is.data.frame(medicalcoder:::..mdcr_internal_pccc_conditions..))
-
-stopifnot(
-  identical(
-    names(medicalcoder:::..mdcr_internal_pccc_conditions..),
-    c("condition", "subcondition", "condition_label", "subcondition_label")
-  )
-)
-
-stopifnot(
-  identical(
-    sapply(medicalcoder:::..mdcr_internal_pccc_conditions.., class),
-    c(condition = "character",
-      subcondition = "character",
-      condition_label = "character",
-      subcondition_label = "character"
-    )
-  )
-)
-
-stopifnot(identical(get_pccc_conditions(), medicalcoder:::..mdcr_internal_pccc_conditions..))
-
-################################################################################
-#                                 End of File                                  #
-################################################################################
diff --git a/tests/test-pccc.R b/tests/test-pccc.R
index 3a7399a9..039fff87 100644
--- a/tests/test-pccc.R
+++ b/tests/test-pccc.R
@@ -1,17 +1,6 @@
 source('utilities.R')
 library(medicalcoder)
 
-################################################################################
-# Verify that the pccc codes are retrievable as a data.frame
-pccc_codes <- get_pccc_codes()
-stopifnot("pccc_codes are a data.frame" = identical(class(pccc_codes), "data.frame"))
-stopifnot(
-  identical(
-    names(pccc_codes),
-    c("icdv", "dx", "full_code", "code", "condition", "subcondition", "transplant_flag", "tech_dep_flag", "pccc_v3.1", "pccc_v3.0", "pccc_v2.1", "pccc_v2.0")
-  )
-)
-
 ################################################################################
 # verify that there is not going to be an error if no matches are found
 dat <- data.frame(patid = 1:26,
@@ -220,6 +209,31 @@ stopifnot(
   !identical(out00$num_cmrb, out07$num_cmrb)
 )
 
+################################################################################
+# looking for the case in v3.1 where the code is a tech and transplant
+techtrans <-
+  subset(get_pccc_codes(), pccc_v3.1 == 1 & transplant_flag == 1 & tech_dep_flag == 1)
+techtrans[["rid"]] <- seq_len(nrow(techtrans))
+
+techtrans_results <-
+  comorbidities(
+    data = techtrans,
+    icd.codes = "code",
+    id.vars = "rid",
+    method = "pccc_v3.1",
+    poa = 1
+  )
+
+for (j in colnames(techtrans_results)) {
+  if (j == "rid") {
+    stopifnot(techtrans_results[[j]] == 1:6)
+  } else if (j %in% c("cvd_tech_only", "cvd_dxpr_or_tech", "any_tech_dep", "any_transplant", "num_cmrb", "cmrb_flag")) {
+    stopifnot(techtrans_results[[j]] == rep(1L, 6))
+  } else {
+    stopifnot(techtrans_results[[j]] == rep(0L, 6))
+  }
+}
+
 ################################################################################
 #                                 End of File                                  #
 ################################################################################
diff --git a/tests/test-summary-pccc.R b/tests/test-summary-pccc.R
index 0aa3baa0..0d93d854 100644
--- a/tests/test-summary-pccc.R
+++ b/tests/test-summary-pccc.R
@@ -121,6 +121,26 @@ stopifnot(
   is.numeric(rtn[["percent"]])
 )
 
+################################################################################
+# PCCC Version 2.1 with flag.method = "cumulative"
+
+cmb <- comorbidities(data = mdcr_longitudinal, id.vars = c("patid", "date"), icd.codes = "code", poa = 1, flag.method = 'cumulative', method = "pccc_v2.1")
+rtn <- tryCatchWarning(summary(cmb))
+stopifnot(inherits(rtn, "warning"))
+rtn <- suppressWarnings(summary(cmb))
+
+stopifnot(
+  inherits(rtn, "data.frame"),
+  identical(
+    names(rtn),
+    c("condition", "label", "count", "percent")
+  ),
+  is.character(rtn[["condition"]]),
+  is.character(rtn[["label"]]),
+  is.integer(rtn[["count"]]),
+  is.numeric(rtn[["percent"]])
+)
+
 ################################################################################
 #                                 End of File                                  #
 ################################################################################
diff --git a/tests/test-tibble-datatable.R b/tests/test-tibble-datatable.R
index 747cc49a..81d7cf7c 100644
--- a/tests/test-tibble-datatable.R
+++ b/tests/test-tibble-datatable.R
@@ -113,6 +113,25 @@ for (obj in ls(envir = DFS, all.names = TRUE)) {
   stopifnot(all.equal(xDF, xDT, check.attributes = FALSE))
 }
 
+# check that the print method returns the input object
+for (obj in ls(envir = DFS, all.names = TRUE)) {
+  x <- print(DFS[[obj]])
+  z <- identical(x, DFS[[obj]])
+  if (!z) {
+    stop(sprintf("print(DFS[['%s']]) does not return identical %s", obj, obj))
+  }
+  x <- print(TBLS[[obj]])
+  z <- identical(x, TBLS[[obj]])
+  if (!z) {
+    stop(sprintf("print(TBLS[['%s']]) does not return identical %s", obj, obj))
+  }
+  x <- print(DTS[[obj]])
+  z <- identical(x, DTS[[obj]])
+  if (!z) {
+    stop(sprintf("print(DTS[['%s']]) does not return identical %s", obj, obj))
+  }
+}
+
 ################################################################################
 # Now, if the data.table namespace is available, then test that the elements in
 # DTS are data.tables and after setting to data.frames, then the objects are
@@ -179,6 +198,8 @@ for (obj in ls(envir = DFS, all.names = TRUE)) {
   stopifnot(identical(xTBL, xDF))
 }
 
+
+
 ################################################################################
 #                                 End of File                                  #
 ################################################################################
diff --git a/tests/test-vs-pccc_1.0.6.R b/tests/test-vs-pccc_1.0.6.R
index 8b584571..d27dda54 100644
--- a/tests/test-vs-pccc_1.0.6.R
+++ b/tests/test-vs-pccc_1.0.6.R
@@ -1,3 +1,4 @@
+library(medicalcoder)
 source('utilities.R')
 ################################################################################
 # objective - the pccc_v2.0 in medicalcoder should reproduce the results from
@@ -7,7 +8,6 @@ source('utilities.R')
 # pccc package only mapped to conditions and did not map subconditions.  this
 # creates a problem with a few codes that were not documented but in the
 # software.  Those will be noted in this script.
-library(medicalcoder)
 
 # get the ICD codes from the medicalcoder package and add a code_id column
 icd_codes <- get_icd_codes()