Decide CA Premium Subsidy eligibility on the exact FPL ratio and adopt the Final 2027 design

changelog.d/ca-premium-subsidy-165-exact-ratio.fixed.md

@@ -0,0 +1 @@
+Decide California Premium Subsidy eligibility on the exact ratio of nonnegative ACA MAGI to prior-year FPL instead of the truncated `aca_magi_fraction`, so PY2026 incomes from 165.003% to 165.994% of FPL are no longer eligible ([2026 Program Design, (d)(7)](https://board.coveredca.com/meetings/2025/July%2028,%202025/CoveredCA_2026_Premium_Subsidy_Program_Design_Final.pdf#page=2): "at or below 165 percent"). Move PY2027 from the superseded Program Design V4 to the [Final 2027 Program Design, (d)(4) and (d)(7)](https://hbex.coveredca.com/data-research/Final-2027-California-Premium-Subsidy-Program-Design.pdf#page=2): 0% up to 150% FPL, 2.8% rising to 5.28% above 150% up to 200% (replacing V4's 2.69%-3.41% and 3.41%-5.1% bands), and eligibility "at or below 200 percent", so households at exactly 200% FPL now qualify.

changelog.d/statute-first-ca-premium-subsidy.fixed.md

@@ -0,0 +1 @@
+Select California Premium Subsidy bands from exact nonnegative ACA MAGI divided by prior-year FPL under the adopted [2026 Program Design, (d)(4)](https://board.coveredca.com/meetings/2025/July%2028,%202025/CoveredCA_2026_Premium_Subsidy_Program_Design_Final.pdf#page=2): exactly 150% changes from a 3.19% contribution to 0%, while income above 150% enters the 3.19% band. Retain the truncated fraction for the rate within that band, following [FTB 3849 Table 1-2 (2020)](https://www.ftb.ca.gov/forms/2020/2020-3849-instructions.pdf#page=6) and [2021](https://www.ftb.ca.gov/forms/2021/2021-3849-instructions.pdf#page=6); [2025 Form 8962 Worksheet 2 line 4](https://www.irs.gov/pub/irs-prior/i8962--2025.pdf#page=9) likewise tests "more than" on the exact amount before truncating.

policyengine_us/parameters/gov/states/ca/hbex/premium_subsidy/applicable_percentage/final.yaml

@@ -4,12 +4,10 @@ values:
   2026-01-01:
     - 0       # 100-150%: flat 0%
     - 0.0391  # 150-165%: ends 3.91%
-  # PY2027 Program Design V4 (adopted Board Res. 2026-22).
-  # Bands: 100-150% FPL, 150-165% FPL, 165-200% FPL.
+  # Final 2027 Program Design. Bands: 100-150% FPL, 150-200% FPL.
   2027-01-01:
     - 0       # 100-150%: flat 0%
-    - 0.0341  # 150-165%: ends 3.41%
-    - 0.051   # 165-200%: ends 5.1%
+    - 0.0528  # 150-200%: ends 5.28%
 
 metadata:
   unit: /1
@@ -20,7 +18,7 @@ metadata:
       href: https://board.coveredca.com/meetings/2025/July%2028,%202025/CoveredCA_2026_Premium_Subsidy_Program_Design_Final.pdf#page=2
     - title: 2026 California State Premium Subsidy Policy Explainer, Table 1
       href: https://hbex.coveredca.com/stakeholders/PDFs/2026-02_StatePremiumSub_PolicyExplainer-Final.pdf#page=2
-    - title: 2027 California Premium Subsidy Program Design V4, subdiv. (d)(4)
-      href: https://board.coveredca.com/meetings/2026/May%2021,%202026/CoveredCA_2027_Premium_Subsidy_Program_Design_V4_05-19-26.pdf#page=2
-    - title: Covered California Board Resolution 2026-22
-      href: https://board.coveredca.com/meetings/2026/June%2018,%202026/2026-22.pdf
+    - title: Final 2027 California Premium Subsidy Program Design, subdiv. (d)(4)
+      href: https://hbex.coveredca.com/data-research/Final-2027-California-Premium-Subsidy-Program-Design.pdf#page=2
+    - title: 2027 California State Premium Subsidy Program Insight, Table 1
+      href: https://hbex.coveredca.com/stakeholders/PDFs/2026-03_StatePremiumSub2027_Insight_Final.pdf#page=2

policyengine_us/parameters/gov/states/ca/hbex/premium_subsidy/applicable_percentage/initial.yaml

@@ -4,12 +4,10 @@ values:
   2026-01-01:
     - 0       # 100-150%: flat 0%
     - 0.0319  # 150-165%: starts 3.19%
-  # PY2027 Program Design V4 (adopted Board Res. 2026-22).
-  # Bands: 100-150% FPL, 150-165% FPL, 165-200% FPL.
+  # Final 2027 Program Design. Bands: 100-150% FPL, 150-200% FPL.
   2027-01-01:
-    - 0       # 100-150%: flat 0%
-    - 0.0269  # 150-165%: starts 2.69%
-    - 0.0341  # 165-200%: starts 3.41%
+    - 0      # 100-150%: flat 0%
+    - 0.028  # 150-200%: starts 2.8%
 
 metadata:
   unit: /1
@@ -20,7 +18,7 @@ metadata:
       href: https://board.coveredca.com/meetings/2025/July%2028,%202025/CoveredCA_2026_Premium_Subsidy_Program_Design_Final.pdf#page=2
     - title: 2026 California State Premium Subsidy Policy Explainer, Table 1
       href: https://hbex.coveredca.com/stakeholders/PDFs/2026-02_StatePremiumSub_PolicyExplainer-Final.pdf#page=2
-    - title: 2027 California Premium Subsidy Program Design V4, subdiv. (d)(4)
-      href: https://board.coveredca.com/meetings/2026/May%2021,%202026/CoveredCA_2027_Premium_Subsidy_Program_Design_V4_05-19-26.pdf#page=2
-    - title: Covered California Board Resolution 2026-22
-      href: https://board.coveredca.com/meetings/2026/June%2018,%202026/2026-22.pdf
+    - title: Final 2027 California Premium Subsidy Program Design, subdiv. (d)(4)
+      href: https://hbex.coveredca.com/data-research/Final-2027-California-Premium-Subsidy-Program-Design.pdf#page=2
+    - title: 2027 California State Premium Subsidy Program Insight, Table 1
+      href: https://hbex.coveredca.com/stakeholders/PDFs/2026-03_StatePremiumSub2027_Insight_Final.pdf#page=2

policyengine_us/parameters/gov/states/ca/hbex/premium_subsidy/applicable_percentage/threshold.yaml

@@ -13,12 +13,11 @@ values:
     - 1
     - 1.5
     - 1.65
-  # PY2027 Program Design V4 (adopted Board Res. 2026-22) widens the top band
-  # to under 200% FPL, adding a 165-200% bracket.
+  # The Final 2027 Program Design has two bands, "100% up to 150%" (0%) and
+  # "Above 150% up to 200%" (2.8% to 5.28%), with no knot at 165%.
   2027-01-01:
     - 1
     - 1.5
-    - 1.65
     - 2.0
 
 metadata:
@@ -30,7 +29,5 @@ metadata:
       href: https://board.coveredca.com/meetings/2025/July%2028,%202025/CoveredCA_2026_Premium_Subsidy_Program_Design_Final.pdf#page=2
     - title: 2026 California State Premium Subsidy Policy Explainer, Table 1
       href: https://hbex.coveredca.com/stakeholders/PDFs/2026-02_StatePremiumSub_PolicyExplainer-Final.pdf#page=2
-    - title: 2027 California Premium Subsidy Program Design V4, subdiv. (d)(4)
-      href: https://board.coveredca.com/meetings/2026/May%2021,%202026/CoveredCA_2027_Premium_Subsidy_Program_Design_V4_05-19-26.pdf#page=2
-    - title: Covered California Board Resolution 2026-22
-      href: https://board.coveredca.com/meetings/2026/June%2018,%202026/2026-22.pdf
+    - title: Final 2027 California Premium Subsidy Program Design, subdiv. (d)(4) and (d)(7)
+      href: https://hbex.coveredca.com/data-research/Final-2027-California-Premium-Subsidy-Program-Design.pdf#page=2

policyengine_us/parameters/gov/states/ca/hbex/premium_subsidy/fpl_limit.yaml

@@ -1,9 +1,16 @@
 description: California limits income eligibility to this share of the federal poverty line under the California Premium Subsidy program.
 values:
+  # Each limit is inclusive and applies to the exact income-to-FPL ratio, not
+  # the truncated aca_magi_fraction.
+  # PY2026 Program Design (d)(7): "at or below 165 percent".
   2026-01-01: 1.65
-  # PY2027 Program Design V4 (adopted Board Res. 2026-22) extends eligibility to
-  # "under 200%" FPL; with 2-decimal FPL-percentage truncation, <= 1.99 == "<200%".
-  2027-01-01: 1.99
+  # Final 2027 Program Design (d)(7): "at or below 200 percent".
+  # The OE27 enroller deck conflicts with (d)(7) at 200%: its summary slide says
+  # the subsidy "applies only to enrollees up to under 200% FPL", while its own
+  # worked example at exactly 200% FPL applies the 5.28% rate. Follow the
+  # adopted Design.
+  # Candidate: us-ca:premium-subsidy-200-fpl-limit until registered.
+  2027-01-01: 2.0
 
 metadata:
   unit: /1
@@ -14,7 +21,9 @@ metadata:
       href: https://board.coveredca.com/meetings/2025/July%2028,%202025/CoveredCA_2026_Premium_Subsidy_Program_Design_Final.pdf#page=2
     - title: 2026 California State Premium Subsidy Policy Explainer, eligibility
       href: https://hbex.coveredca.com/stakeholders/PDFs/2026-02_StatePremiumSub_PolicyExplainer-Final.pdf#page=1
-    - title: 2027 California Premium Subsidy Program Design V4, subdiv. (d)(7)
-      href: https://board.coveredca.com/meetings/2026/May%2021,%202026/CoveredCA_2027_Premium_Subsidy_Program_Design_V4_05-19-26.pdf#page=2
-    - title: Covered California Board Resolution 2026-22
-      href: https://board.coveredca.com/meetings/2026/June%2018,%202026/2026-22.pdf
+    - title: Final 2027 California Premium Subsidy Program Design, subdiv. (d)(7)
+      href: https://hbex.coveredca.com/data-research/Final-2027-California-Premium-Subsidy-Program-Design.pdf#page=2
+    - title: 2027 California State Premium Subsidy Program Insight, eligibility
+      href: https://hbex.coveredca.com/stakeholders/PDFs/2026-03_StatePremiumSub2027_Insight_Final.pdf#page=1
+    - title: "Covered California OE 2027 Enroller Kick-off, 200% FPL example #page 37-40"
+      href: https://hbex.coveredca.com/toolkit/webinars-briefings/downloads/OE27_Enroller_Kickoff.pdf#page=37

policyengine_us/parameters/gov/states/ca/hbex/premium_subsidy/in_effect.yaml

@@ -1,13 +1,15 @@
 description: California provides state premium subsidies when this is true under the California Premium Subsidy program.
 values:
   # The provision runs from PY2026, matching the New Mexico and Maryland approach
-  # (ending 2028-01-01). PY2026 and PY2027 both have board-adopted, verified
-  # program designs: the PY2027 Program Design V4 (adopted Board Resolution
-  # 2026-22, June 18 2026; funded by the 2026 Budget Act $300M HCARF) changes the
-  # schedule, so PY2027 is NOT a carry-forward of PY2026 (see the applicable
-  # percentage and fpl_limit files). Section 100800(c) has the Exchange adopt the
-  # design annually upon appropriation and Section 100825 creates no entitlement,
-  # so the provision ends 2028-01-01 absent a verified PY2028 design.
+  # (ending 2028-01-01). PY2026 and PY2027 both have adopted, verified program
+  # designs: the Final 2027 Program Design (adopted under item 4800-101-3381 of
+  # the Budget Act of 2026; the 2027 Insight reports $300M appropriated from
+  # the Health Care Affordability Reserve Fund) changes the schedule, so PY2027
+  # is NOT a carry-forward of PY2026 (see the applicable percentage and
+  # fpl_limit files).
+  # Section 100800(c) has the Exchange adopt the design annually upon
+  # appropriation and Section 100825 creates no entitlement, so the provision
+  # ends 2028-01-01 absent a verified PY2028 design.
   #
   # The Program Design's enhanced-PTC trigger ("state subsidy applies if the
   # federal enhanced PTC is not extended by Sept 30 2025") fired, so the residual
@@ -25,6 +27,10 @@ metadata:
   reference:
     - title: 2026 California Premium Subsidy Program Design, preamble
       href: https://board.coveredca.com/meetings/2025/July%2028,%202025/CoveredCA_2026_Premium_Subsidy_Program_Design_Final.pdf#page=1
+    - title: Final 2027 California Premium Subsidy Program Design, preamble
+      href: https://hbex.coveredca.com/data-research/Final-2027-California-Premium-Subsidy-Program-Design.pdf#page=1
+    - title: 2027 California State Premium Subsidy Program Insight, background
+      href: https://hbex.coveredca.com/stakeholders/PDFs/2026-03_StatePremiumSub2027_Insight_Final.pdf#page=1
     - title: CA Gov. Code Section 100800(c) (Exchange adopts annual program design upon appropriation)
       href: https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=GOV&sectionNum=100800.
     - title: CA Gov. Code Section 100825

policyengine_us/tests/code_health/test_source_conflicts.py

@@ -125,6 +125,7 @@
     "policyengine_us/parameters/gov/ssa/ssi/income/ism/food_counts.yaml": 1,
     "policyengine_us/parameters/gov/states/ar/ade/oec/sra/rates/no_copay_smi_threshold.yaml": 1,
     "policyengine_us/parameters/gov/states/ca/cpuc/income_sources.yaml": 1,
+    "policyengine_us/parameters/gov/states/ca/hbex/premium_subsidy/fpl_limit.yaml": 1,
     "policyengine_us/parameters/gov/states/co/doi/premium_assistance/amount/additional_member.yaml": 1,
     "policyengine_us/parameters/gov/states/co/doi/premium_assistance/amount/first_member.yaml": 1,
     "policyengine_us/parameters/gov/states/fl/commerce/liheap/payment/base_amount.yaml": 1,

policyengine_us/tests/policy/baseline/gov/states/ca/hbex/premium_subsidy/ca_premium_subsidy.yaml

@@ -13,6 +13,7 @@
 # The negative-MAGI clamp case supplies eligibility and a positive rate to
 # isolate the amount formula; its income fraction is correctly zero.
 #   CA schedule: threshold [1.0, 1.5, 1.65], initial [0, 0.0319], final [0, 0.0391]
+#   PY2027 (Final Design): threshold [1.0, 1.5, 2.0], initial [0, 0.028], final [0, 0.0528]
 
 # ---- 100-150% FPL band (applicable percentage 0%) ----
 
@@ -99,8 +100,9 @@
     ca_premium_subsidy: 3_112.50
 
 - name: Case 4, exactly 165% FPL positive subsidy (pct 3.91%, top of the ramp).
-  # pct = 0.0391 (final rate). income 26_000.
-  # amount = max(0, 7_000 - 2_500 - 0.0391*26_000) = 7_000 - 2_500 - 1_016.60 = 3_483.40.
+  # pct = 0.0391 (final rate). income 25_822.50 = 165% of the 2025 one-person
+  # FPG $15,650, the highest income "at or below 165 percent".
+  # amount = max(0, 7_000 - 2_500 - 0.0391*25_822.50) = 7_000 - 2_500 - 1_009.66 = 3_490.34.
   period: 2026
   absolute_error_margin: 0.01
   input:
@@ -112,8 +114,8 @@
       tax_unit:
         members: [person1]
         tax_unit_fpg:
-          2025: 15_757.575757575758
-        aca_magi: 26_000
+          2025: 15_650
+        aca_magi: 25_822.50
         aca_magi_fraction: 1.65
         slcsp: 7_000
         aca_ptc: 2_500
@@ -123,7 +125,8 @@
         members: [person1]
         state_code: CA
   output:
-    ca_premium_subsidy: 3_483.40
+    ca_premium_subsidy_eligible: true
+    ca_premium_subsidy: 3_490.34
 
 - name: Case 5, 160% FPL with expected contribution exceeding the gap -> $0 floor.
   # pct = 0.0319 + (2/3)*0.0072 = 0.0367. income 24_000 -> 0.0367*24_000 = 880.80.
@@ -259,6 +262,7 @@
         aca_magi_fraction: 1.66
         slcsp: 6_000
         aca_ptc: 2_000
+        tax_unit_is_filer: true
     households:
       household:
         members: [person1]
@@ -295,9 +299,10 @@
 # ---- Floor edge with a positive amount ----
 
 - name: Case 11, exactly at the 100% FPL floor (1.0) with a positive subsidy.
-  # magi_frac 1.0 -> pct 0 (flat 100-150% band). Eligible: 1.0 >= fpl_floor 1.0,
-  # <= fpl_limit 1.65, in effect, APTC-eligible. income 15_000.
-  # amount = max(0, 6_000 - 3_500 - 0*15_000) = 2_500. Confirms the floor edge is
+  # magi_frac 1.0 -> pct 0 (flat 100-150% band). Eligible: income 15_650 is
+  # exactly the 2025 one-person FPG, so 1.0 >= fpl_floor 1.0, <= fpl_limit 1.65,
+  # in effect, APTC-eligible.
+  # amount = max(0, 6_000 - 3_500 - 0*15_650) = 2_500. Confirms the floor edge is
   # eligible AND pays the full post-APTC gap (pct is 0 at the bottom of the band).
   period: 2026
   absolute_error_margin: 0.01
@@ -310,8 +315,8 @@
       tax_unit:
         members: [person1]
         tax_unit_fpg:
-          2025: 15_000
-        aca_magi: 15_000
+          2025: 15_650
+        aca_magi: 15_650
         aca_magi_fraction: 1.00
         slcsp: 6_000
         aca_ptc: 3_500
@@ -321,6 +326,7 @@
         members: [person1]
         state_code: CA
   output:
+    ca_premium_subsidy_eligible: true
     ca_premium_subsidy: 2_500
 
 # ---- Mid-band interaction: APTC and pct both active, residual positive ----
@@ -409,6 +415,7 @@
         aca_magi_fraction: 1.66
         slcsp: 6_000
         aca_ptc: 2_000
+        tax_unit_is_filer: true
     households:
       household:
         members: [person1]
@@ -439,6 +446,7 @@
         aca_magi_fraction: 0.99
         slcsp: 6_000
         aca_ptc: 2_000
+        tax_unit_is_filer: true
     households:
       household:
         members: [person1]
@@ -447,15 +455,16 @@
     ca_premium_subsidy_applicable_percentage: 0
     ca_premium_subsidy: 0
 
-# ---- PY2027 carry-forward (positive amount) ----
+# ---- PY2027 Final Program Design (positive amount) ----
 
 - name: Case 16, PY2027 pays a positive subsidy at 157.5% FPL (revised schedule).
-  # in_effect is true through PY2027 and the schedule CHANGED (Board Res. 2026-22):
-  # the 150-165% band is now initial 0.0269 -> final 0.0341, so
-  # magi_frac 1.575 -> pct 0.0269 + 0.5*(0.0341-0.0269) = 0.0269 + 0.0036 = 0.0305.
-  # income 25_000. amount = max(0, 6_000 - 2_000 - 0.0305*25_000)
-  # = 6_000 - 2_000 - 762.50 = 3_237.50 (up from the 2026 value of 3_112.50 at the
-  # same FPL because the PY2027 applicable percentage in this band is lower).
+  # in_effect is true through PY2027 and the Final 2027 Program Design (d)(4)
+  # changes the schedule: one paying band "Above 150% up to 200%", initial
+  # 0.028 -> final 0.0528. magi_frac 1.575 -> position (1.575-1.5)/0.5 = 0.15
+  # -> pct 0.028 + 0.15*0.0248 = 0.03172. income 25_000.
+  # amount = max(0, 6_000 - 2_000 - 0.03172*25_000) = 6_000 - 2_000 - 793 = 3_207
+  # (up from the 2026 value of 3_112.50 at the same FPL because the PY2027
+  # applicable percentage at this point is lower).
   period: 2027
   absolute_error_margin: 0.01
   input:
@@ -478,7 +487,7 @@
         members: [person1]
         state_code: CA
   output:
-    ca_premium_subsidy: 3_237.50
+    ca_premium_subsidy: 3_207
 
 # ---- Floor from the SLCSP == APTC direction ----
 
@@ -551,3 +560,43 @@
     ca_premium_subsidy_eligible: true
     ca_premium_subsidy_applicable_percentage: 0.0355
     ca_premium_subsidy: 3_881.75
+
+# ---- PY2027 upper limit (Covered California's worked example) ----
+
+- name: Case 19, PY2027 exactly 200% FPL pays the 1.5-point gap (OE27 example).
+  # The OE27 enroller deck (PDF pages 37-38) works a single 40-year-old in
+  # Sacramento County at $31,920, exactly 200% of the 2026 one-person FPG
+  # $15,960: benchmark $688 a month, federal required contribution 6.78%,
+  # state rate 5.28% (6.78% - 1.5%), state subsidy about $40 a month.
+  # slcsp = 688*12 = 8_256. aca_ptc = 8_256 - 0.0678*31_920 = 8_256 - 2_164.176
+  # = 6_091.824. Eligible: 2.0 is "at or below 200 percent" (Design (d)(7)).
+  # amount = max(0, 8_256 - 6_091.824 - 0.0528*31_920)
+  # = 2_164.176 - 1_685.376 = 478.80 = 0.015*31_920, or $39.90 a month.
+  # aca_ptc is derived from the federal 2027 applicable percentage table
+  # (Rev. Proc. 2026-26, PolicyEngine/policyengine-us#10443), which gives 6.78%
+  # at exactly 200% FPL. The output pins that federal credit.
+  period: 2027
+  absolute_error_margin: 0.01
+  input:
+    people:
+      person1:
+        age: 40
+        is_aca_ptc_eligible: true
+    tax_units:
+      tax_unit:
+        members: [person1]
+        tax_unit_fpg:
+          2026: 15_960
+        aca_magi: 31_920
+        aca_magi_fraction: 2.00
+        slcsp: 8_256
+        tax_unit_is_filer: true
+    households:
+      household:
+        members: [person1]
+        state_code: CA
+  output:
+    aca_ptc: 6_091.824
+    ca_premium_subsidy_eligible: true
+    ca_premium_subsidy_applicable_percentage: 0.0528
+    ca_premium_subsidy: 478.80