diff --git a/src/mjlab/envs/manager_based_env.py b/src/mjlab/envs/manager_based_env.py
index 5eed68ed4..96b6ec2b8 100644
--- a/src/mjlab/envs/manager_based_env.py
+++ b/src/mjlab/envs/manager_based_env.py
@@ -74,15 +74,7 @@ def load_managers(self) -> None:
     self.event_manager = EventManager(self.cfg.events, self)
     print("[INFO] Event manager: ", self.event_manager)
 
-    expanded_model_fields: list[str] = []
-    if "startup" in self.event_manager.available_modes:
-      for event_cfg in self.event_manager._mode_term_cfgs["startup"]:
-        if "field" in event_cfg.params:
-          expanded_model_fields.append(event_cfg.params["field"])
-        # Special handling for actuator gain randomization.
-        if event_cfg.func.__name__ == "randomize_actuator_gains":
-          expanded_model_fields.extend(["actuator_gainprm", "actuator_biasprm"])
-    self.sim.expand_model_fields(expanded_model_fields)
+    self.sim.expand_model_fields(self.event_manager.domain_randomization_fields)
 
     self.action_manager = ActionManager(self.cfg.actions, self)
     print("[INFO] Action Manager:", self.action_manager)
diff --git a/src/mjlab/managers/event_manager.py b/src/mjlab/managers/event_manager.py
index 709c38153..da259fde0 100644
--- a/src/mjlab/managers/event_manager.py
+++ b/src/mjlab/managers/event_manager.py
@@ -20,6 +20,7 @@ def __init__(self, cfg: object, env: ManagerBasedEnv):
     self._mode_term_names: dict[EventMode, list[str]] = dict()
     self._mode_term_cfgs: dict[EventMode, list[EventTermCfg]] = dict()
     self._mode_class_term_cfgs: dict[EventMode, list[EventTermCfg]] = dict()
+    self._domain_randomization_fields: list[str] = list()
 
     super().__init__(cfg=cfg, env=env)
 
@@ -42,6 +43,15 @@ def __str__(self) -> str:
           table.add_row([index, name])
       msg += table.get_string()
       msg += "\n"
+    if self._domain_randomization_fields:
+      table = PrettyTable()
+      table.title = "Domain Randomization Fields"
+      table.field_names = ["Index", "Field Name"]
+      table.align["Field Name"] = "l"
+      for index, field in enumerate(self._domain_randomization_fields):
+        table.add_row([index, field])
+      msg += table.get_string()
+      msg += "\n"
     return msg
 
   # Properties.
@@ -54,6 +64,10 @@ def active_terms(self) -> dict[EventMode, list[str]]:
   def available_modes(self) -> list[EventMode]:
     return list(self._mode_term_names.keys())
 
+  @property
+  def domain_randomization_fields(self) -> list[str]:
+    return self._domain_randomization_fields
+
   # Methods.
 
   def reset(self, env_ids: torch.Tensor | slice | None = None):
@@ -182,3 +196,8 @@ def _prepare_terms(self) -> None:
         self._reset_term_last_triggered_step_id.append(step_count)
         no_trigger = torch.zeros(self.num_envs, device=self.device, dtype=torch.bool)
         self._reset_term_last_triggered_once.append(no_trigger)
+
+      if term_cfg.func.__name__ == "randomize_field":
+        field_name = term_cfg.params["field"]
+        if field_name not in self._domain_randomization_fields:
+          self._domain_randomization_fields.append(field_name)