diff --git a/changelog_entry.yaml b/changelog_entry.yaml
index e69de29bb2d..d57a5ed12a8 100644
--- a/changelog_entry.yaml
+++ b/changelog_entry.yaml
@@ -0,0 +1,4 @@
+- bump: patch
+  changes:
+    fixed:
+    - Delaware TANF deficit rate parameter history extended to 2017 to cover full-year simulations.
diff --git a/policyengine_us/parameters/gov/states/de/dhss/tanf/benefit/deficit_rate.yaml b/policyengine_us/parameters/gov/states/de/dhss/tanf/benefit/deficit_rate.yaml
index 955f70aa6c1..ed2dcb8155f 100644
--- a/policyengine_us/parameters/gov/states/de/dhss/tanf/benefit/deficit_rate.yaml
+++ b/policyengine_us/parameters/gov/states/de/dhss/tanf/benefit/deficit_rate.yaml
@@ -1,7 +1,7 @@
 description: Delaware uses this share of the deficit to calculate the grant remainder under the Temporary Assistance for Needy Families program.
 
 values:
-  2024-10-01: 0.5
+  2017-01-01: 0.5
 
 metadata:
   unit: /1