From 61e4a158fe8b60cc9cd97a16896a171677f6acf2 Mon Sep 17 00:00:00 2001
From: Daphne Hansell <128793799+daphnehanse11@users.noreply.github.com>
Date: Thu, 30 Apr 2026 15:53:40 -0400
Subject: [PATCH 1/4] Use actual bronze premium for selected marketplace plans

---
 changelog.d/changed/8211.md                   |  1 +
 .../gov/aca/ptc/marketplace_net_premium.yaml  | 14 +++++++++++
 ...lected_marketplace_plan_premium_proxy.yaml | 23 +++++++++++++++++++
 .../baseline/gov/aca/ptc/used_aca_ptc.yaml    | 20 +++++++++++++++-
 .../ptc/selected_marketplace_plan_category.py | 15 ++++++++++++
 ...selected_marketplace_plan_premium_proxy.py | 17 ++++++++++++--
 6 files changed, 87 insertions(+), 3 deletions(-)
 create mode 100644 changelog.d/changed/8211.md
 create mode 100644 policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_category.py

diff --git a/changelog.d/changed/8211.md b/changelog.d/changed/8211.md
new file mode 100644
index 00000000000..ed1c99d0cef
--- /dev/null
+++ b/changelog.d/changed/8211.md
@@ -0,0 +1 @@
+Use actual lowest-cost bronze premiums when Bronze is the selected Marketplace plan category.
diff --git a/policyengine_us/tests/policy/baseline/gov/aca/ptc/marketplace_net_premium.yaml b/policyengine_us/tests/policy/baseline/gov/aca/ptc/marketplace_net_premium.yaml
index 21cdf7daa90..ddf141f5162 100644
--- a/policyengine_us/tests/policy/baseline/gov/aca/ptc/marketplace_net_premium.yaml
+++ b/policyengine_us/tests/policy/baseline/gov/aca/ptc/marketplace_net_premium.yaml
@@ -41,3 +41,17 @@
     selected_marketplace_plan_premium_proxy: 8_000
     used_aca_ptc: 0
     marketplace_net_premium: 8_000
+
+- name: Bronze selected plan net premium uses actual bronze premium.
+  absolute_error_margin: 0.01
+  period: 2026
+  input:
+    pays_aca_premium: true
+    selected_marketplace_plan_category: BRONZE
+    slcsp: 10_000
+    lcbp: 5_000
+    aca_ptc: 3_000
+  output:
+    selected_marketplace_plan_premium_proxy: 5_000
+    used_aca_ptc: 3_000
+    marketplace_net_premium: 2_000
diff --git a/policyengine_us/tests/policy/baseline/gov/aca/ptc/selected_marketplace_plan_premium_proxy.yaml b/policyengine_us/tests/policy/baseline/gov/aca/ptc/selected_marketplace_plan_premium_proxy.yaml
index 039ca1137b2..24ef11f2628 100644
--- a/policyengine_us/tests/policy/baseline/gov/aca/ptc/selected_marketplace_plan_premium_proxy.yaml
+++ b/policyengine_us/tests/policy/baseline/gov/aca/ptc/selected_marketplace_plan_premium_proxy.yaml
@@ -63,3 +63,26 @@
     pays_aca_premium: true
     is_aca_ptc_eligible: false
     selected_marketplace_plan_premium_proxy: 8_000
+
+- name: Case 6, bronze selected plan uses the lowest-cost bronze premium.
+  absolute_error_margin: 0.01
+  period: 2026
+  input:
+    pays_aca_premium: true
+    selected_marketplace_plan_category: BRONZE
+    slcsp: 10_000
+    lcbp: 6_500
+  output:
+    selected_marketplace_plan_premium_proxy: 6_500
+
+- name: Case 7, silver selected plan keeps the benchmark-ratio proxy.
+  absolute_error_margin: 0.01
+  period: 2026
+  input:
+    pays_aca_premium: true
+    selected_marketplace_plan_category: SILVER
+    slcsp: 10_000
+    lcbp: 6_500
+    selected_marketplace_plan_benchmark_ratio: 0.9
+  output:
+    selected_marketplace_plan_premium_proxy: 9_000
diff --git a/policyengine_us/tests/policy/baseline/gov/aca/ptc/used_aca_ptc.yaml b/policyengine_us/tests/policy/baseline/gov/aca/ptc/used_aca_ptc.yaml
index 3c04f3d7eff..c1f36cf129c 100644
--- a/policyengine_us/tests/policy/baseline/gov/aca/ptc/used_aca_ptc.yaml
+++ b/policyengine_us/tests/policy/baseline/gov/aca/ptc/used_aca_ptc.yaml
@@ -13,7 +13,7 @@
     used_aca_ptc: 200
     unused_aca_ptc: 0
 
-- name: Case 2, a bronze-like ratio leaves some ACA PTC unused.
+- name: Case 2, a lower-than-benchmark selected-plan ratio leaves some ACA PTC unused.
   absolute_error_margin: 0.01
   period: 2025
   input:
@@ -56,3 +56,21 @@
     selected_marketplace_plan_premium_proxy: 0
     used_aca_ptc: 0
     unused_aca_ptc: 200
+
+- name: Case 5, bronze selected plan uses actual bronze premium before applying PTC.
+  absolute_error_margin: 0.01
+  period: 2026
+  input:
+    is_aca_ptc_eligible: true
+    pays_aca_premium: true
+    selected_marketplace_plan_category: BRONZE
+    slcsp: 10_000
+    lcbp: 7_000
+    aca_magi: 20_000
+    aca_required_contribution_percentage: 0.04
+    tax_unit_is_filer: true
+  output:
+    aca_ptc: 9_200
+    selected_marketplace_plan_premium_proxy: 7_000
+    used_aca_ptc: 7_000
+    unused_aca_ptc: 2_200
diff --git a/policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_category.py b/policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_category.py
new file mode 100644
index 00000000000..a1d6ae04ed5
--- /dev/null
+++ b/policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_category.py
@@ -0,0 +1,15 @@
+from policyengine_us.model_api import *
+
+
+class MarketplacePlanCategory(Enum):
+    BRONZE = "Bronze"
+    SILVER = "Silver"
+
+
+class selected_marketplace_plan_category(Variable):
+    value_type = Enum
+    possible_values = MarketplacePlanCategory
+    default_value = MarketplacePlanCategory.SILVER
+    entity = TaxUnit
+    label = "Selected Marketplace plan category"
+    definition_period = YEAR
diff --git a/policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_premium_proxy.py b/policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_premium_proxy.py
index 604dc448498..873517e42df 100644
--- a/policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_premium_proxy.py
+++ b/policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_premium_proxy.py
@@ -1,4 +1,7 @@
 from policyengine_us.model_api import *
+from policyengine_us.variables.gov.aca.ptc.selected_marketplace_plan_category import (
+    MarketplacePlanCategory,
+)
 
 
 class selected_marketplace_plan_premium_proxy(Variable):
@@ -12,9 +15,19 @@ def formula(tax_unit, period, parameters):
         takes_up_aca_if_eligible = tax_unit("takes_up_aca_if_eligible", period)
         person = tax_unit.members
         pays_marketplace_premium = tax_unit.sum(person("pays_aca_premium", period)) > 0
+        selected_plan_category = tax_unit(
+            "selected_marketplace_plan_category", period
+        )
+        silver_premium = tax_unit("slcsp", period) * tax_unit(
+            "selected_marketplace_plan_benchmark_ratio", period
+        )
+        selected_plan_premium = where(
+            selected_plan_category == MarketplacePlanCategory.BRONZE,
+            tax_unit("lcbp", period),
+            silver_premium,
+        )
         return where(
             takes_up_aca_if_eligible & pays_marketplace_premium,
-            tax_unit("slcsp", period)
-            * tax_unit("selected_marketplace_plan_benchmark_ratio", period),
+            selected_plan_premium,
             0,
         )

From db709c2fe3564b0424f95b093c65c05efbee84d0 Mon Sep 17 00:00:00 2001
From: Daphne Hansell <128793799+daphnehanse11@users.noreply.github.com>
Date: Thu, 30 Apr 2026 16:04:48 -0400
Subject: [PATCH 2/4] Format selected marketplace plan premium proxy

---
 .../gov/aca/ptc/selected_marketplace_plan_premium_proxy.py    | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_premium_proxy.py b/policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_premium_proxy.py
index 873517e42df..2772a7f3d33 100644
--- a/policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_premium_proxy.py
+++ b/policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_premium_proxy.py
@@ -15,9 +15,7 @@ def formula(tax_unit, period, parameters):
         takes_up_aca_if_eligible = tax_unit("takes_up_aca_if_eligible", period)
         person = tax_unit.members
         pays_marketplace_premium = tax_unit.sum(person("pays_aca_premium", period)) > 0
-        selected_plan_category = tax_unit(
-            "selected_marketplace_plan_category", period
-        )
+        selected_plan_category = tax_unit("selected_marketplace_plan_category", period)
         silver_premium = tax_unit("slcsp", period) * tax_unit(
             "selected_marketplace_plan_benchmark_ratio", period
         )

From 090045290305f1ff123bcef14a4ac86e92521751 Mon Sep 17 00:00:00 2001
From: Daphne Hansell <128793799+daphnehanse11@users.noreply.github.com>
Date: Thu, 30 Apr 2026 16:20:46 -0400
Subject: [PATCH 3/4] Add ACA cost-sharing reduction actuarial values

---
 changelog.d/added/8188.md                     |  1 +
 changelog.d/changed/8211.md                   |  1 -
 .../gov/aca/csr/actuarial_value/highest.yaml  | 10 ++++
 .../gov/aca/csr/actuarial_value/lowest.yaml   | 10 ++++
 .../gov/aca/csr/actuarial_value/middle.yaml   | 10 ++++
 .../income_threshold/highest_av_maximum.yaml  | 10 ++++
 .../gov/aca/csr/income_threshold/maximum.yaml | 10 ++++
 .../income_threshold/middle_av_maximum.yaml   | 10 ++++
 .../gov/aca/csr/income_threshold/minimum.yaml | 10 ++++
 .../gov/aca/metal_actuarial_value/bronze.yaml | 10 ++++
 .../gov/aca/metal_actuarial_value/silver.yaml | 10 ++++
 .../gov/aca/csr/marketplace_csr_category.yaml | 53 +++++++++++++++++++
 .../gov/aca/csr/marketplace_csr_eligible.yaml | 28 ++++++++++
 ...marketplace_effective_actuarial_value.yaml | 14 +++++
 .../csr/marketplace_csr_actuarial_value.py    | 26 +++++++++
 .../gov/aca/csr/marketplace_csr_category.py   | 36 +++++++++++++
 .../gov/aca/csr/marketplace_csr_eligible.py   | 22 ++++++++
 .../marketplace_effective_actuarial_value.py  | 18 +++++++
 ...lected_marketplace_plan_actuarial_value.py | 18 +++++++
 19 files changed, 306 insertions(+), 1 deletion(-)
 create mode 100644 changelog.d/added/8188.md
 delete mode 100644 changelog.d/changed/8211.md
 create mode 100644 policyengine_us/parameters/gov/aca/csr/actuarial_value/highest.yaml
 create mode 100644 policyengine_us/parameters/gov/aca/csr/actuarial_value/lowest.yaml
 create mode 100644 policyengine_us/parameters/gov/aca/csr/actuarial_value/middle.yaml
 create mode 100644 policyengine_us/parameters/gov/aca/csr/income_threshold/highest_av_maximum.yaml
 create mode 100644 policyengine_us/parameters/gov/aca/csr/income_threshold/maximum.yaml
 create mode 100644 policyengine_us/parameters/gov/aca/csr/income_threshold/middle_av_maximum.yaml
 create mode 100644 policyengine_us/parameters/gov/aca/csr/income_threshold/minimum.yaml
 create mode 100644 policyengine_us/parameters/gov/aca/metal_actuarial_value/bronze.yaml
 create mode 100644 policyengine_us/parameters/gov/aca/metal_actuarial_value/silver.yaml
 create mode 100644 policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_csr_category.yaml
 create mode 100644 policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_csr_eligible.yaml
 create mode 100644 policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_effective_actuarial_value.yaml
 create mode 100644 policyengine_us/variables/gov/aca/csr/marketplace_csr_actuarial_value.py
 create mode 100644 policyengine_us/variables/gov/aca/csr/marketplace_csr_category.py
 create mode 100644 policyengine_us/variables/gov/aca/csr/marketplace_csr_eligible.py
 create mode 100644 policyengine_us/variables/gov/aca/csr/marketplace_effective_actuarial_value.py
 create mode 100644 policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_actuarial_value.py

diff --git a/changelog.d/added/8188.md b/changelog.d/added/8188.md
new file mode 100644
index 00000000000..514eff1a274
--- /dev/null
+++ b/changelog.d/added/8188.md
@@ -0,0 +1 @@
+Add selected Marketplace plan categories and ACA cost-sharing reduction actuarial value variables.
diff --git a/changelog.d/changed/8211.md b/changelog.d/changed/8211.md
deleted file mode 100644
index ed1c99d0cef..00000000000
--- a/changelog.d/changed/8211.md
+++ /dev/null
@@ -1 +0,0 @@
-Use actual lowest-cost bronze premiums when Bronze is the selected Marketplace plan category.
diff --git a/policyengine_us/parameters/gov/aca/csr/actuarial_value/highest.yaml b/policyengine_us/parameters/gov/aca/csr/actuarial_value/highest.yaml
new file mode 100644
index 00000000000..7329bea0ba9
--- /dev/null
+++ b/policyengine_us/parameters/gov/aca/csr/actuarial_value/highest.yaml
@@ -0,0 +1,10 @@
+description: The Affordable Care Act sets this actuarial value for the highest ordinary silver cost-sharing reduction plan variation.
+values:
+  2014-01-01: 0.94
+metadata:
+  unit: /1
+  period: year
+  label: ACA CSR highest silver plan actuarial value
+  reference:
+    - title: 45 CFR § 156.420(a)(1)(ii) - Plan variations
+      href: https://www.law.cornell.edu/cfr/text/45/156.420#a_1_ii
diff --git a/policyengine_us/parameters/gov/aca/csr/actuarial_value/lowest.yaml b/policyengine_us/parameters/gov/aca/csr/actuarial_value/lowest.yaml
new file mode 100644
index 00000000000..997f7478d6a
--- /dev/null
+++ b/policyengine_us/parameters/gov/aca/csr/actuarial_value/lowest.yaml
@@ -0,0 +1,10 @@
+description: The Affordable Care Act sets this actuarial value for the lowest ordinary silver cost-sharing reduction plan variation.
+values:
+  2014-01-01: 0.73
+metadata:
+  unit: /1
+  period: year
+  label: ACA CSR lowest silver plan actuarial value
+  reference:
+    - title: 45 CFR § 156.420(a)(3)(ii) - Plan variations
+      href: https://www.law.cornell.edu/cfr/text/45/156.420#a_3_ii
diff --git a/policyengine_us/parameters/gov/aca/csr/actuarial_value/middle.yaml b/policyengine_us/parameters/gov/aca/csr/actuarial_value/middle.yaml
new file mode 100644
index 00000000000..c62968148d8
--- /dev/null
+++ b/policyengine_us/parameters/gov/aca/csr/actuarial_value/middle.yaml
@@ -0,0 +1,10 @@
+description: The Affordable Care Act sets this actuarial value for the middle ordinary silver cost-sharing reduction plan variation.
+values:
+  2014-01-01: 0.87
+metadata:
+  unit: /1
+  period: year
+  label: ACA CSR middle silver plan actuarial value
+  reference:
+    - title: 45 CFR § 156.420(a)(2)(ii) - Plan variations
+      href: https://www.law.cornell.edu/cfr/text/45/156.420#a_2_ii
diff --git a/policyengine_us/parameters/gov/aca/csr/income_threshold/highest_av_maximum.yaml b/policyengine_us/parameters/gov/aca/csr/income_threshold/highest_av_maximum.yaml
new file mode 100644
index 00000000000..9d333bcaf90
--- /dev/null
+++ b/policyengine_us/parameters/gov/aca/csr/income_threshold/highest_av_maximum.yaml
@@ -0,0 +1,10 @@
+description: The Affordable Care Act sets this maximum household income threshold for the highest ordinary cost-sharing reduction actuarial value.
+values:
+  2014-01-01: 1.5
+metadata:
+  unit: /1
+  period: year
+  label: ACA CSR highest actuarial value income threshold
+  reference:
+    - title: 45 CFR § 155.305(g)(2)(i) - Eligibility standards
+      href: https://www.law.cornell.edu/cfr/text/45/155.305#g_2_i
diff --git a/policyengine_us/parameters/gov/aca/csr/income_threshold/maximum.yaml b/policyengine_us/parameters/gov/aca/csr/income_threshold/maximum.yaml
new file mode 100644
index 00000000000..026bd678627
--- /dev/null
+++ b/policyengine_us/parameters/gov/aca/csr/income_threshold/maximum.yaml
@@ -0,0 +1,10 @@
+description: The Affordable Care Act sets this maximum household income threshold for ordinary income-based cost-sharing reductions.
+values:
+  2014-01-01: 2.5
+metadata:
+  unit: /1
+  period: year
+  label: ACA CSR maximum income threshold
+  reference:
+    - title: 45 CFR § 155.305(g)(1)(i)(C) - Eligibility standards
+      href: https://www.law.cornell.edu/cfr/text/45/155.305#g_1_i_C
diff --git a/policyengine_us/parameters/gov/aca/csr/income_threshold/middle_av_maximum.yaml b/policyengine_us/parameters/gov/aca/csr/income_threshold/middle_av_maximum.yaml
new file mode 100644
index 00000000000..0bc1d71bc17
--- /dev/null
+++ b/policyengine_us/parameters/gov/aca/csr/income_threshold/middle_av_maximum.yaml
@@ -0,0 +1,10 @@
+description: The Affordable Care Act sets this maximum household income threshold for the middle ordinary cost-sharing reduction actuarial value.
+values:
+  2014-01-01: 2
+metadata:
+  unit: /1
+  period: year
+  label: ACA CSR middle actuarial value income threshold
+  reference:
+    - title: 45 CFR § 155.305(g)(2)(ii) - Eligibility standards
+      href: https://www.law.cornell.edu/cfr/text/45/155.305#g_2_ii
diff --git a/policyengine_us/parameters/gov/aca/csr/income_threshold/minimum.yaml b/policyengine_us/parameters/gov/aca/csr/income_threshold/minimum.yaml
new file mode 100644
index 00000000000..89c136cc607
--- /dev/null
+++ b/policyengine_us/parameters/gov/aca/csr/income_threshold/minimum.yaml
@@ -0,0 +1,10 @@
+description: The Affordable Care Act sets this minimum household income threshold for ordinary income-based cost-sharing reductions.
+values:
+  2014-01-01: 1
+metadata:
+  unit: /1
+  period: year
+  label: ACA CSR minimum income threshold
+  reference:
+    - title: 45 CFR § 155.305(g)(2)(i) - Eligibility standards
+      href: https://www.law.cornell.edu/cfr/text/45/155.305#g_2_i
diff --git a/policyengine_us/parameters/gov/aca/metal_actuarial_value/bronze.yaml b/policyengine_us/parameters/gov/aca/metal_actuarial_value/bronze.yaml
new file mode 100644
index 00000000000..a66873519be
--- /dev/null
+++ b/policyengine_us/parameters/gov/aca/metal_actuarial_value/bronze.yaml
@@ -0,0 +1,10 @@
+description: The Affordable Care Act sets this actuarial value for bronze Marketplace plans.
+values:
+  2014-01-01: 0.6
+metadata:
+  unit: /1
+  period: year
+  label: ACA bronze plan actuarial value
+  reference:
+    - title: 45 CFR § 156.140(b)(1) - Levels of coverage
+      href: https://www.law.cornell.edu/cfr/text/45/156.140#b_1
diff --git a/policyengine_us/parameters/gov/aca/metal_actuarial_value/silver.yaml b/policyengine_us/parameters/gov/aca/metal_actuarial_value/silver.yaml
new file mode 100644
index 00000000000..9a90e5f5c5c
--- /dev/null
+++ b/policyengine_us/parameters/gov/aca/metal_actuarial_value/silver.yaml
@@ -0,0 +1,10 @@
+description: The Affordable Care Act sets this actuarial value for silver Marketplace plans.
+values:
+  2014-01-01: 0.7
+metadata:
+  unit: /1
+  period: year
+  label: ACA silver plan actuarial value
+  reference:
+    - title: 45 CFR § 156.140(b)(2) - Levels of coverage
+      href: https://www.law.cornell.edu/cfr/text/45/156.140#b_2
diff --git a/policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_csr_category.yaml b/policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_csr_category.yaml
new file mode 100644
index 00000000000..25888017bdd
--- /dev/null
+++ b/policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_csr_category.yaml
@@ -0,0 +1,53 @@
+- name: Case 1, silver enrollee at 125 percent FPL receives 94 percent AV CSR.
+  absolute_error_margin: 0.001
+  period: 2026
+  input:
+    is_aca_ptc_eligible: true
+    aca_magi_fraction: 1.25
+    selected_marketplace_plan_category: SILVER
+  output:
+    person_receives_aca: true
+    marketplace_csr_eligible: true
+    marketplace_csr_category: AV_94
+    selected_marketplace_plan_actuarial_value: 0.7
+    marketplace_csr_actuarial_value: 0.94
+    marketplace_effective_actuarial_value: 0.94
+
+- name: Case 2, silver enrollee at 175 percent FPL receives 87 percent AV CSR.
+  absolute_error_margin: 0.001
+  period: 2026
+  input:
+    is_aca_ptc_eligible: true
+    aca_magi_fraction: 1.75
+    selected_marketplace_plan_category: SILVER
+  output:
+    marketplace_csr_eligible: true
+    marketplace_csr_category: AV_87
+    marketplace_csr_actuarial_value: 0.87
+    marketplace_effective_actuarial_value: 0.87
+
+- name: Case 3, silver enrollee at 225 percent FPL receives 73 percent AV CSR.
+  absolute_error_margin: 0.001
+  period: 2026
+  input:
+    is_aca_ptc_eligible: true
+    aca_magi_fraction: 2.25
+    selected_marketplace_plan_category: SILVER
+  output:
+    marketplace_csr_eligible: true
+    marketplace_csr_category: AV_73
+    marketplace_csr_actuarial_value: 0.73
+    marketplace_effective_actuarial_value: 0.73
+
+- name: Case 4, silver enrollee at 275 percent FPL receives no CSR.
+  absolute_error_margin: 0.001
+  period: 2026
+  input:
+    is_aca_ptc_eligible: true
+    aca_magi_fraction: 2.75
+    selected_marketplace_plan_category: SILVER
+  output:
+    marketplace_csr_eligible: false
+    marketplace_csr_category: NONE
+    marketplace_csr_actuarial_value: 0
+    marketplace_effective_actuarial_value: 0.7
diff --git a/policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_csr_eligible.yaml b/policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_csr_eligible.yaml
new file mode 100644
index 00000000000..6195cefd67e
--- /dev/null
+++ b/policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_csr_eligible.yaml
@@ -0,0 +1,28 @@
+- name: Case 1, bronze enrollee is ineligible for ordinary CSR.
+  absolute_error_margin: 0.001
+  period: 2026
+  input:
+    is_aca_ptc_eligible: true
+    aca_magi_fraction: 1.25
+    selected_marketplace_plan_category: BRONZE
+  output:
+    marketplace_csr_eligible: false
+    marketplace_csr_category: NONE
+    selected_marketplace_plan_actuarial_value: 0.6
+    marketplace_csr_actuarial_value: 0
+    marketplace_effective_actuarial_value: 0.6
+
+- name: Case 2, silver enrollee without PTC eligibility is ineligible for CSR.
+  absolute_error_margin: 0.001
+  period: 2026
+  input:
+    is_aca_ptc_eligible: false
+    aca_magi_fraction: 1.25
+    selected_marketplace_plan_category: SILVER
+  output:
+    person_receives_aca: false
+    marketplace_csr_eligible: false
+    marketplace_csr_category: NONE
+    selected_marketplace_plan_actuarial_value: 0.7
+    marketplace_csr_actuarial_value: 0
+    marketplace_effective_actuarial_value: 0.7
diff --git a/policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_effective_actuarial_value.yaml b/policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_effective_actuarial_value.yaml
new file mode 100644
index 00000000000..729120a7362
--- /dev/null
+++ b/policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_effective_actuarial_value.yaml
@@ -0,0 +1,14 @@
+- name: Case 1, CSR changes effective actuarial value but not Marketplace net premium.
+  absolute_error_margin: 0.001
+  period: 2026
+  input:
+    is_aca_ptc_eligible: true
+    aca_magi_fraction: 1.25
+    selected_marketplace_plan_category: SILVER
+    selected_marketplace_plan_premium_proxy: 5_000
+    used_aca_ptc: 3_000
+  output:
+    selected_marketplace_plan_actuarial_value: 0.7
+    marketplace_csr_category: AV_94
+    marketplace_effective_actuarial_value: 0.94
+    marketplace_net_premium: 2_000
diff --git a/policyengine_us/variables/gov/aca/csr/marketplace_csr_actuarial_value.py b/policyengine_us/variables/gov/aca/csr/marketplace_csr_actuarial_value.py
new file mode 100644
index 00000000000..fa4dbf1914f
--- /dev/null
+++ b/policyengine_us/variables/gov/aca/csr/marketplace_csr_actuarial_value.py
@@ -0,0 +1,26 @@
+from policyengine_us.model_api import *
+from policyengine_us.variables.gov.aca.csr.marketplace_csr_category import (
+    MarketplaceCSRCategory,
+)
+
+
+class marketplace_csr_actuarial_value(Variable):
+    value_type = float
+    entity = TaxUnit
+    label = "Marketplace cost-sharing reduction actuarial value"
+    unit = "/1"
+    definition_period = YEAR
+    reference = "https://www.law.cornell.edu/cfr/text/45/156.420#a"
+    defined_for = "marketplace_csr_eligible"
+
+    def formula(tax_unit, period, parameters):
+        category = tax_unit("marketplace_csr_category", period)
+        p = parameters(period).gov.aca.csr.actuarial_value
+        return select(
+            [
+                category == MarketplaceCSRCategory.AV_94,
+                category == MarketplaceCSRCategory.AV_87,
+                category == MarketplaceCSRCategory.AV_73,
+            ],
+            [p.highest, p.middle, p.lowest],
+        )
diff --git a/policyengine_us/variables/gov/aca/csr/marketplace_csr_category.py b/policyengine_us/variables/gov/aca/csr/marketplace_csr_category.py
new file mode 100644
index 00000000000..f747bf51f51
--- /dev/null
+++ b/policyengine_us/variables/gov/aca/csr/marketplace_csr_category.py
@@ -0,0 +1,36 @@
+from policyengine_us.model_api import *
+
+
+class MarketplaceCSRCategory(Enum):
+    NONE = "None"
+    AV_94 = "94 percent actuarial value"
+    AV_87 = "87 percent actuarial value"
+    AV_73 = "73 percent actuarial value"
+
+
+class marketplace_csr_category(Variable):
+    value_type = Enum
+    possible_values = MarketplaceCSRCategory
+    default_value = MarketplaceCSRCategory.NONE
+    entity = TaxUnit
+    label = "Marketplace cost-sharing reduction category"
+    definition_period = YEAR
+    reference = "https://www.law.cornell.edu/cfr/text/45/155.305#g_2"
+
+    def formula(tax_unit, period, parameters):
+        eligible = tax_unit("marketplace_csr_eligible", period)
+        magi_fraction = tax_unit("aca_magi_fraction", period)
+        p = parameters(period).gov.aca.csr.income_threshold
+        return select(
+            [
+                eligible & (magi_fraction <= p.highest_av_maximum),
+                eligible & (magi_fraction <= p.middle_av_maximum),
+                eligible & (magi_fraction <= p.maximum),
+            ],
+            [
+                MarketplaceCSRCategory.AV_94,
+                MarketplaceCSRCategory.AV_87,
+                MarketplaceCSRCategory.AV_73,
+            ],
+            default=MarketplaceCSRCategory.NONE,
+        )
diff --git a/policyengine_us/variables/gov/aca/csr/marketplace_csr_eligible.py b/policyengine_us/variables/gov/aca/csr/marketplace_csr_eligible.py
new file mode 100644
index 00000000000..bf2cfd73c14
--- /dev/null
+++ b/policyengine_us/variables/gov/aca/csr/marketplace_csr_eligible.py
@@ -0,0 +1,22 @@
+from policyengine_us.model_api import *
+from policyengine_us.variables.gov.aca.ptc.selected_marketplace_plan_category import (
+    MarketplacePlanCategory,
+)
+
+
+class marketplace_csr_eligible(Variable):
+    value_type = bool
+    entity = TaxUnit
+    label = "Tax unit is eligible for ordinary Marketplace cost-sharing reductions"
+    definition_period = YEAR
+    reference = "https://www.law.cornell.edu/cfr/text/45/155.305#g_1"
+
+    def formula(tax_unit, period, parameters):
+        person = tax_unit.members
+        receives_aca = tax_unit.sum(person("person_receives_aca", period)) > 0
+        category = tax_unit("selected_marketplace_plan_category", period)
+        silver_selected = category == MarketplacePlanCategory.SILVER
+        magi_fraction = tax_unit("aca_magi_fraction", period)
+        p = parameters(period).gov.aca.csr.income_threshold
+        income_eligible = (magi_fraction >= p.minimum) & (magi_fraction <= p.maximum)
+        return receives_aca & silver_selected & income_eligible
diff --git a/policyengine_us/variables/gov/aca/csr/marketplace_effective_actuarial_value.py b/policyengine_us/variables/gov/aca/csr/marketplace_effective_actuarial_value.py
new file mode 100644
index 00000000000..94b84815fe6
--- /dev/null
+++ b/policyengine_us/variables/gov/aca/csr/marketplace_effective_actuarial_value.py
@@ -0,0 +1,18 @@
+from policyengine_us.model_api import *
+
+
+class marketplace_effective_actuarial_value(Variable):
+    value_type = float
+    entity = TaxUnit
+    label = "Marketplace selected plan effective actuarial value"
+    unit = "/1"
+    definition_period = YEAR
+    reference = (
+        "https://www.law.cornell.edu/cfr/text/45/156.140#b",
+        "https://www.law.cornell.edu/cfr/text/45/156.420#a",
+    )
+
+    def formula(tax_unit, period, parameters):
+        selected_plan_av = tax_unit("selected_marketplace_plan_actuarial_value", period)
+        csr_av = tax_unit("marketplace_csr_actuarial_value", period)
+        return max_(selected_plan_av, csr_av)
diff --git a/policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_actuarial_value.py b/policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_actuarial_value.py
new file mode 100644
index 00000000000..aeca2481fa0
--- /dev/null
+++ b/policyengine_us/variables/gov/aca/ptc/selected_marketplace_plan_actuarial_value.py
@@ -0,0 +1,18 @@
+from policyengine_us.model_api import *
+from policyengine_us.variables.gov.aca.ptc.selected_marketplace_plan_category import (
+    MarketplacePlanCategory,
+)
+
+
+class selected_marketplace_plan_actuarial_value(Variable):
+    value_type = float
+    entity = TaxUnit
+    label = "Selected Marketplace plan actuarial value"
+    unit = "/1"
+    definition_period = YEAR
+    reference = "https://www.law.cornell.edu/cfr/text/45/156.140#b"
+
+    def formula(tax_unit, period, parameters):
+        category = tax_unit("selected_marketplace_plan_category", period)
+        p = parameters(period).gov.aca.metal_actuarial_value
+        return where(category == MarketplacePlanCategory.BRONZE, p.bronze, p.silver)

From 3fdaad44b2c9a4e077832893aa844ced871f5931 Mon Sep 17 00:00:00 2001
From: Daphne Hansell <128793799+daphnehanse11@users.noreply.github.com>
Date: Mon, 4 May 2026 09:55:10 -0400
Subject: [PATCH 4/4] Fix CSR eligibility below poverty line

---
 .../gov/aca/csr/income_threshold/minimum.yaml      | 10 ----------
 .../gov/aca/csr/marketplace_csr_category.yaml      | 14 ++++++++++++++
 .../gov/aca/csr/marketplace_csr_eligible.py        |  5 +++--
 3 files changed, 17 insertions(+), 12 deletions(-)
 delete mode 100644 policyengine_us/parameters/gov/aca/csr/income_threshold/minimum.yaml

diff --git a/policyengine_us/parameters/gov/aca/csr/income_threshold/minimum.yaml b/policyengine_us/parameters/gov/aca/csr/income_threshold/minimum.yaml
deleted file mode 100644
index 89c136cc607..00000000000
--- a/policyengine_us/parameters/gov/aca/csr/income_threshold/minimum.yaml
+++ /dev/null
@@ -1,10 +0,0 @@
-description: The Affordable Care Act sets this minimum household income threshold for ordinary income-based cost-sharing reductions.
-values:
-  2014-01-01: 1
-metadata:
-  unit: /1
-  period: year
-  label: ACA CSR minimum income threshold
-  reference:
-    - title: 45 CFR § 155.305(g)(2)(i) - Eligibility standards
-      href: https://www.law.cornell.edu/cfr/text/45/155.305#g_2_i
diff --git a/policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_csr_category.yaml b/policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_csr_category.yaml
index 25888017bdd..7798bf29dc4 100644
--- a/policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_csr_category.yaml
+++ b/policyengine_us/tests/policy/baseline/gov/aca/csr/marketplace_csr_category.yaml
@@ -51,3 +51,17 @@
     marketplace_csr_category: NONE
     marketplace_csr_actuarial_value: 0
     marketplace_effective_actuarial_value: 0.7
+
+- name: Case 5, APTC-eligible silver enrollee below 100 percent FPL receives 94 percent AV CSR.
+  absolute_error_margin: 0.001
+  period: 2026
+  input:
+    is_aca_ptc_eligible: true
+    aca_magi_fraction: 0.75
+    selected_marketplace_plan_category: SILVER
+  output:
+    person_receives_aca: true
+    marketplace_csr_eligible: true
+    marketplace_csr_category: AV_94
+    marketplace_csr_actuarial_value: 0.94
+    marketplace_effective_actuarial_value: 0.94
diff --git a/policyengine_us/variables/gov/aca/csr/marketplace_csr_eligible.py b/policyengine_us/variables/gov/aca/csr/marketplace_csr_eligible.py
index bf2cfd73c14..05d9f668320 100644
--- a/policyengine_us/variables/gov/aca/csr/marketplace_csr_eligible.py
+++ b/policyengine_us/variables/gov/aca/csr/marketplace_csr_eligible.py
@@ -17,6 +17,7 @@ def formula(tax_unit, period, parameters):
         category = tax_unit("selected_marketplace_plan_category", period)
         silver_selected = category == MarketplacePlanCategory.SILVER
         magi_fraction = tax_unit("aca_magi_fraction", period)
-        p = parameters(period).gov.aca.csr.income_threshold
-        income_eligible = (magi_fraction >= p.minimum) & (magi_fraction <= p.maximum)
+        income_eligible = (
+            magi_fraction <= parameters(period).gov.aca.csr.income_threshold.maximum
+        )
         return receives_aca & silver_selected & income_eligible