diff --git a/changelog_entry.yaml b/changelog_entry.yaml
index e69de29b..914486b8 100644
--- a/changelog_entry.yaml
+++ b/changelog_entry.yaml
@@ -0,0 +1,4 @@
+- bump: minor
+  changes:
+    added:
+    - Baseline parameter node.
diff --git a/policyengine_core/taxbenefitsystems/tax_benefit_system.py b/policyengine_core/taxbenefitsystems/tax_benefit_system.py
index f8ced593..c30d3d95 100644
--- a/policyengine_core/taxbenefitsystems/tax_benefit_system.py
+++ b/policyengine_core/taxbenefitsystems/tax_benefit_system.py
@@ -125,6 +125,7 @@ def __init__(self, entities: Sequence[Entity] = None, reform=None) -> None:
 
         if self.parameters_dir is not None:
             self.load_parameters(self.parameters_dir)
+            self.parameters.add_child("baseline", self.parameters.clone())
             if reform:
                 self.apply_reform_set(reform)
             self.parameters = homogenize_parameter_structures(