diff --git a/pyomo/contrib/parmest/parmest.py b/pyomo/contrib/parmest/parmest.py
index 1dc0b8dc66d..8d0dc89fcd1 100644
--- a/pyomo/contrib/parmest/parmest.py
+++ b/pyomo/contrib/parmest/parmest.py
@@ -440,7 +440,7 @@ def TotalCost_rule(model):
             )
 
         # Convert theta Params to Vars, and unfix theta Vars
-        theta_CUIDs = [v for k, v in model.unknown_parameters.items()]
+        theta_CUIDs = list(model.unknown_parameters.values())
         parmest_model = utils.convert_params_to_vars(model, theta_CUIDs, fix_vars=False)
 
         return parmest_model
diff --git a/pyomo/contrib/parmest/tests/test_utils.py b/pyomo/contrib/parmest/tests/test_utils.py
index dfb3ade7aec..ef0e3b64f91 100644
--- a/pyomo/contrib/parmest/tests/test_utils.py
+++ b/pyomo/contrib/parmest/tests/test_utils.py
@@ -50,7 +50,7 @@ def test_convert_param_to_var(self):
         exp = ReactorDesignExperiment(data, 0)
         instance = exp.get_labeled_model()
 
-        param_CUIDs = [v for k, v in instance.unknown_parameters.items()]
+        param_CUIDs = list(instance.unknown_parameters.values())
         m_vars = parmest.utils.convert_params_to_vars(
             instance, param_CUIDs, fix_vars=True
         )
@@ -120,7 +120,7 @@ def label_model(self):
         exp = RooneyBieglerExperimentIndexedParams(self.data.loc[0, :])
         instance = exp.get_labeled_model()
 
-        param_CUIDs = [v for k, v in instance.unknown_parameters.items()]
+        param_CUIDs = list(instance.unknown_parameters.values())
         m_vars = parmest.utils.convert_params_to_vars(
             instance, param_CUIDs, fix_vars=True
         )
diff --git a/pyomo/contrib/parmest/utils/model_utils.py b/pyomo/contrib/parmest/utils/model_utils.py
index 74f5ea389d5..83d2566bbec 100644
--- a/pyomo/contrib/parmest/utils/model_utils.py
+++ b/pyomo/contrib/parmest/utils/model_utils.py
@@ -80,9 +80,9 @@ def convert_params_to_vars(model, param_CUIDs=None, fix_vars=False):
             vals = theta_object.extract_values()
 
             # get indexed Params
-            param_theta_objects = [theta_obj for _, theta_obj in theta_object.items()]
-
-            # get indexed Param names
+            param_theta_objects = list(theta_object.values())
+            
+            # get indexed Param CUIDs
             indexed_param_CUIDs.extend(
                 ComponentUID(theta_obj) for theta_obj in theta_object.values()
             )
@@ -135,8 +135,7 @@ def convert_params_to_vars(model, param_CUIDs=None, fix_vars=False):
 
     # Convert Params to Vars in Expressions
     for expr in model.component_data_objects(pyo.Expression):
-        if expr.active and any(
-            ComponentUID(v) in param_CUIDs_set
+        if any(ComponentUID(v) in param_CUIDs_set
             for v in identify_mutable_parameters(expr)
         ):
             new_expr = replace_expressions(expr=expr, substitution_map=substitution_map)