Keep a filer who can be claimed as a dependent out of the premium tax credit family, and apply each state premium program's rule

changelog.d/claimable-filer-ptc.fixed.md

@@ -0,0 +1,9 @@
+Apply IRC 36B(c)(1)(D) to the premium tax credit: a filer who can be claimed as a dependent on another return is outside the tax family (26 CFR 1.36B-1(d)(2)), so the credit uses the tax family size for the poverty line and the coverage family's benchmark premium, on a joint return the other spouse keeps the credit, and the Washington, Massachusetts, Connecticut, Colorado, Maryland, California, New Mexico, Vermont and New Jersey premium programs follow their own rules for that person.
+
+Preserve supplied benchmark premiums, NY dependent predicates and Medicaid MAGI; rank only enrolled children; test every insured member for shared-policy CSR eligibility; infer both minor joint filers; and allocate shared premiums by coverage month, with zero allocation for empty enrollment.
+
+Count enrolled nonpayers in Washington Cascade Care Savings Group 2 before applying the household premium cap.
+
+Complete partially inferred joint ACA filers without an adult age cutoff, and use the completed set for tax-family membership and MAGI additions.
+
+Honor supplied ACA family-tier child predicates for nonpayers in their supplied month while retaining uncapped calculated classifications in other months.

policyengine_us/reforms/aca/aca_ptc_700_fpl_cliff.py

@@ -66,7 +66,16 @@ def formula(person, period, parameters):
             )
             is_income_eligible = standard_income_eligible | below_fpl_exception
 
-            return person("pays_aca_premium", period) & ~separate & is_income_eligible
+            # The reform leaves 26 U.S.C. 36B(c)(1)(D) in place: someone
+            # another taxpayer can claim is outside the tax family.
+            tax_family_member = person("is_aca_tax_family_member", period)
+
+            return (
+                person("pays_aca_premium", period)
+                & tax_family_member
+                & ~separate
+                & is_income_eligible
+            )
 
     class reform(Reform):
         def apply(self):

policyengine_us/reforms/aca/aca_ptc_additional_bracket.py

@@ -73,11 +73,16 @@ def formula(person, period, parameters):
             child_pays = person("aca_child_index", period) <= p_aca.max_child_count
             pays_aca_premium = is_aca_adult | child_pays
 
+            # The reform leaves 26 U.S.C. 36B(c)(1)(D) in place: someone
+            # another taxpayer can claim is outside the tax family.
+            tax_family_member = person("is_aca_tax_family_member", period)
+
             return (
                 is_status_eligible
                 & is_coverage_eligible
                 & is_income_eligible
                 & pays_aca_premium
+                & tax_family_member
             )
 
     class reform(Reform):

policyengine_us/reforms/aca/aca_ptc_simplified_bracket.py

@@ -74,11 +74,16 @@ def formula(person, period, parameters):
             child_pays = person("aca_child_index", period) <= p_aca.max_child_count
             pays_aca_premium = is_aca_adult | child_pays
 
+            # The reform leaves 26 U.S.C. 36B(c)(1)(D) in place: someone
+            # another taxpayer can claim is outside the tax family.
+            tax_family_member = person("is_aca_tax_family_member", period)
+
             return (
                 is_status_eligible
                 & is_coverage_eligible
                 & is_income_eligible
                 & pays_aca_premium
+                & tax_family_member
             )
 
     class reform(Reform):