Split SSI couple amount for OAP

changelog_entry.yaml

@@ -0,0 +1,4 @@
+- bump: patch
+  changes:
+    fixed:
+      - Split SSI couple amount for OAP

policyengine_us/tests/policy/baseline/gov/states/co/ssa/oap/co_oap.yaml

@@ -4,6 +4,7 @@
     co_oap_eligible: true
     ssi_countable_income: 1_000
     ssi: 0
+    ssi_marital_both_eligible: false
   output:
     co_oap: 10_424
 
@@ -13,6 +14,7 @@
     co_oap_eligible: true
     ssi_countable_income: 0
     ssi: 2_000
+    ssi_marital_both_eligible: false
   output:
     co_oap: 9_424
 
@@ -22,5 +24,26 @@
     co_oap_eligible: true
     ssi_countable_income: 6_000
     ssi: 6_000
+    ssi_marital_both_eligible: false
   output:
     co_oap: 0
+
+- name: SSI both eligible
+  period: 2024
+  input:
+    people:
+      head:
+        co_oap_eligible: true
+        ssi_countable_income: 0
+        ssi: 12_000
+        ssi_marital_both_eligible: true
+      spouse:
+        co_oap_eligible: true
+        ssi_countable_income: 0
+        ssi: 0
+        ssi_marital_both_eligible: true
+    marital_units:
+      marital_unit:
+        members: [head, spouse]
+  output:
+    co_oap: [5_784, 5_784]

policyengine_us/variables/gov/states/co/ssa/oap/co_oap.py

@@ -10,8 +10,13 @@ class co_oap(Variable):
 
     def formula(person, period, parameters):
         income = person("ssi_countable_income", period)
+        both_eligible = person("ssi_marital_both_eligible", period)
         ssi = person("ssi", period)
-        total_countable_income = ssi + income
+        # The SSI variable assigns SSI to one member of the marital unit if both are eligible
+        marital_ssi = where(
+            both_eligible, person.marital_unit.sum(ssi) / 2, ssi
+        )
+        total_countable_income = marital_ssi + income
         p = parameters(period).gov.states.co.ssa.oap
         grant_standard = p.grant_standard * MONTHS_IN_YEAR
         return max_(0, grant_standard - total_countable_income)