diff --git a/changelog.d/cdcc-disabled-dependent-expenses.fixed.md b/changelog.d/cdcc-disabled-dependent-expenses.fixed.md
new file mode 100644
index 00000000000..edc9f92b7f5
--- /dev/null
+++ b/changelog.d/cdcc-disabled-dependent-expenses.fixed.md
@@ -0,0 +1 @@
+Fix the Child and Dependent Care Credit (and its state mirrors) for households whose qualifying individual is a disabled adult: attribute childcare expenses to disabled dependents and spouses of any age, count a disabled spouse who is modeled as the tax unit head, and apply the IRC section 21(d)(2) deemed earned income for a student or incapacitated spouse. Also scope the DC Keep Child Care Affordable Tax Credit to child-only care expenses, so a disabled adult dependent sharing a household with an eligible child does not inflate this under-4 child credit.
diff --git a/policyengine_us/parameters/gov/irs/credits/cdcc/deemed_earned_income.yaml b/policyengine_us/parameters/gov/irs/credits/cdcc/deemed_earned_income.yaml
new file mode 100644
index 00000000000..6dd883f7f7a
--- /dev/null
+++ b/policyengine_us/parameters/gov/irs/credits/cdcc/deemed_earned_income.yaml
@@ -0,0 +1,19 @@
+description: The IRS deems a spouse who is a full-time student or incapable of self-care to have at least this earned income for the Child and Dependent Care Credit, based on the number of qualifying individuals.
+brackets:
+  - threshold:
+      2013-01-01: 0
+    amount:
+      2013-01-01: 3_000
+  - threshold:
+      2013-01-01: 2
+    amount:
+      2013-01-01: 6_000
+metadata:
+  type: single_amount
+  threshold_unit: person
+  amount_unit: currency-USD
+  period: year
+  label: CDCC deemed earned income for student or disabled spouse
+  reference:
+    - title: 26 U.S. Code § 21(d)(2)
+      href: https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title26-section21&num=0&edition=prelim
diff --git a/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/cdcc.yaml b/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/cdcc.yaml
index d010ed7d1b7..7a1be889164 100644
--- a/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/cdcc.yaml
+++ b/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/cdcc.yaml
@@ -31,3 +31,41 @@
     cdcc_potential: 1_000
   output:
     cdcc: 0
+
+# IRC 21(e)(2): a married taxpayer may only claim the credit on a joint return.
+- name: Married filing separately does not receive the credit
+  period: 2024
+  input:
+    cdcc_credit_limit: 1_000
+    cdcc_potential: 1_000
+    filing_status: SEPARATE
+  output:
+    cdcc: 0
+
+- name: Head of household receives the credit
+  period: 2024
+  input:
+    cdcc_credit_limit: 1_000
+    cdcc_potential: 1_000
+    filing_status: HEAD_OF_HOUSEHOLD
+  output:
+    cdcc: 1_000
+
+- name: Married filing separately with a child and care expenses gets zero
+  absolute_error_margin: 0.01
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 35
+        employment_income: 40_000
+        is_tax_unit_head: true
+      person2:
+        age: 5
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+        filing_status: SEPARATE
+        tax_unit_childcare_expenses: 3_000
+  output:
+    cdcc: 0
diff --git a/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/cdcc_income_floor_eligible.yaml b/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/cdcc_income_floor_eligible.yaml
new file mode 100644
index 00000000000..b860477ba45
--- /dev/null
+++ b/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/cdcc_income_floor_eligible.yaml
@@ -0,0 +1,40 @@
+- name: Case 1, disabled spouse assigned as tax unit head is eligible for the income floor.
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 70
+        is_incapable_of_self_care: true
+      person2:
+        age: 50
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+  output:
+    is_tax_unit_head: [true, false]
+    is_tax_unit_spouse: [false, true]
+    cdcc_income_floor_eligible: [true, false]
+
+- name: Case 2, disabled single tax unit head is not eligible for the spouse income floor.
+  period: 2024
+  input:
+    age: 40
+    is_incapable_of_self_care: true
+    is_tax_unit_head: true
+  output:
+    cdcc_income_floor_eligible: false
+
+- name: Case 3, full-time student spouse is eligible for the income floor.
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 50
+      person2:
+        age: 45
+        is_full_time_student: true
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+  output:
+    cdcc_income_floor_eligible: [false, true]
diff --git a/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/count_cdcc_eligible.yaml b/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/count_cdcc_eligible.yaml
new file mode 100644
index 00000000000..b0246dc3499
--- /dev/null
+++ b/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/count_cdcc_eligible.yaml
@@ -0,0 +1,97 @@
+- name: Both spouses incapable of self-care count as one qualifying individual
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 45
+        is_incapable_of_self_care: true
+      person2:
+        age: 43
+        is_incapable_of_self_care: true
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+        filing_status: JOINT
+  output:
+    # Both are is_cdcc_eligible, but only one spouse is a qualifying individual
+    # (the other is the taxpayer) per IRC 21(b)(1)(C).
+    is_cdcc_eligible: [true, true]
+    count_cdcc_eligible: 1
+
+- name: Disabled spouse plus a young child count as two qualifying individuals
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 45
+        is_incapable_of_self_care: true
+      person2:
+        age: 43
+      person3:
+        age: 5
+    tax_units:
+      tax_unit:
+        members: [person1, person2, person3]
+        filing_status: JOINT
+  output:
+    count_cdcc_eligible: 2
+
+- name: Both disabled spouses plus a child count as two qualifying individuals
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 45
+        is_incapable_of_self_care: true
+      person2:
+        age: 43
+        is_incapable_of_self_care: true
+      person3:
+        age: 5
+    tax_units:
+      tax_unit:
+        members: [person1, person2, person3]
+        filing_status: JOINT
+  output:
+    count_cdcc_eligible: 2
+
+- name: Two disabled adult dependents count as two qualifying individuals
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 45
+      person2:
+        age: 20
+        is_incapable_of_self_care: true
+        is_tax_unit_head: false
+        is_tax_unit_spouse: false
+      person3:
+        age: 22
+        is_incapable_of_self_care: true
+        is_tax_unit_head: false
+        is_tax_unit_spouse: false
+    tax_units:
+      tax_unit:
+        members: [person1, person2, person3]
+  output:
+    count_cdcc_eligible: 2
+
+- name: Healthy couple with two young children count as two qualifying individuals
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 45
+      person2:
+        age: 43
+      person3:
+        age: 5
+      person4:
+        age: 8
+    tax_units:
+      tax_unit:
+        members: [person1, person2, person3, person4]
+        filing_status: JOINT
+  output:
+    count_cdcc_eligible: 2
diff --git a/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/integration.yaml b/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/integration.yaml
index c0210fa2edd..c100f878466 100644
--- a/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/integration.yaml
+++ b/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/integration.yaml
@@ -95,3 +95,72 @@
   output:  # expected results from patched TAXSIM35 2023-01-13 version
     taxsim_tfica: 11_130.24
     income_tax: 24_507.2
+
+- name: Disabled adult dependent's care expenses reach the CDCC expense base
+  absolute_error_margin: 0.01
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 40
+        employment_income: 40_000
+        is_tax_unit_head: true
+      person2:
+        age: 38
+        employment_income: 30_000
+      person3:  # disabled adult dependent, the only qualifying individual
+        age: 40
+        is_incapable_of_self_care: true
+        is_tax_unit_head: false
+    spm_units:
+      spm_unit:
+        members: [person1, person2, person3]
+        spm_unit_pre_subsidy_childcare_expenses: 6_000
+    tax_units:
+      tax_unit:
+        members: [person1, person2, person3]
+    households:
+      household:
+        members: [person1, person2, person3]
+        state_code: KS
+  output:
+    # Only the disabled non-head adult is a dependent care recipient.
+    is_dependent_care_recipient: [false, false, true]
+    # The $6,000 SPM expense now flows to the tax unit (was $0 before the fix
+    # because the dependent is no longer a child under 18). This becomes the
+    # CDCC expense base via cdcc_relevant_expenses.
+    tax_unit_childcare_expenses: 6_000
+    cdcc_relevant_expenses: 3_000
+    cdcc: 660
+
+- name: Both spouses incapable of self-care are one qualifying individual
+  absolute_error_margin: 0.01
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 45
+        employment_income: 50_000
+        is_incapable_of_self_care: true
+      person2:
+        age: 43
+        is_incapable_of_self_care: true
+    spm_units:
+      spm_unit:
+        members: [person1, person2]
+        spm_unit_pre_subsidy_childcare_expenses: 6_000
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+        filing_status: JOINT
+    households:
+      household:
+        members: [person1, person2]
+        state_code: TX
+  output:
+    # Two incapacitated spouses = one qualifying individual (the taxpayer is
+    # not their own), so the cap and the deemed floor are $3,000, not $6,000.
+    # cdcc = 20% x $3,000 = $600 (was $1,200 before the fix double-counted).
+    count_cdcc_eligible: 1
+    cdcc_limit: 3_000
+    cdcc: 600
diff --git a/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/is_cdcc_eligible.yaml b/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/is_cdcc_eligible.yaml
new file mode 100644
index 00000000000..bf0002a18ae
--- /dev/null
+++ b/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/is_cdcc_eligible.yaml
@@ -0,0 +1,43 @@
+- name: Case 1, dependent child under age 13 qualifies.
+  period: 2024
+  input:
+    age: 12
+    is_tax_unit_head: false
+    is_tax_unit_spouse: false
+  output:
+    is_cdcc_eligible: true
+
+- name: Case 2, dependent child age 13 does not qualify by age.
+  period: 2024
+  input:
+    age: 13
+    is_tax_unit_head: false
+    is_tax_unit_spouse: false
+  output:
+    is_cdcc_eligible: false
+
+- name: Case 3, disabled single tax unit head is not their own qualifying individual.
+  period: 2024
+  input:
+    age: 40
+    is_incapable_of_self_care: true
+    is_tax_unit_head: true
+  output:
+    is_cdcc_eligible: false
+
+- name: Case 4, disabled spouse assigned as tax unit head qualifies.
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 70
+        is_incapable_of_self_care: true
+      person2:
+        age: 50
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+  output:
+    is_tax_unit_head: [true, false]
+    is_tax_unit_spouse: [false, true]
+    is_cdcc_eligible: [true, false]
diff --git a/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/min_head_spouse_earned.yaml b/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/min_head_spouse_earned.yaml
index b3ab1c31637..56b2a935d09 100644
--- a/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/min_head_spouse_earned.yaml
+++ b/policyengine_us/tests/policy/baseline/gov/irs/credits/cdcc/min_head_spouse_earned.yaml
@@ -1,18 +1,34 @@
 - name: Head earns less
   period: 2018
   input:
-    head_earned: 1
-    spouse_earned: 2
-    tax_unit_is_joint: true
+    people:
+      person1:
+        is_tax_unit_head: true
+        adjusted_earnings: 1
+      person2:
+        is_tax_unit_spouse: true
+        adjusted_earnings: 2
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+        filing_status: JOINT
   output:
     min_head_spouse_earned: 1
 
 - name: Spouse earns less
   period: 2018
   input:
-    head_earned: 2
-    spouse_earned: 1
-    tax_unit_is_joint: true
+    people:
+      person1:
+        is_tax_unit_head: true
+        adjusted_earnings: 2
+      person2:
+        is_tax_unit_spouse: true
+        adjusted_earnings: 1
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+        filing_status: JOINT
   output:
     min_head_spouse_earned: 1
 
@@ -22,3 +38,87 @@
     head_earned: 1
   output:
     min_head_spouse_earned: 1
+
+- name: Disabled spouse assigned as tax unit head receives one-person income floor
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 70
+        is_incapable_of_self_care: true
+      person2:
+        age: 50
+        employment_income: 50_000
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+        filing_status: JOINT
+  output:
+    is_tax_unit_head: [true, false]
+    is_tax_unit_spouse: [false, true]
+    count_cdcc_eligible: 1
+    min_head_spouse_earned: 3_000
+
+- name: Disabled spouse assigned as tax unit head receives two-person income floor
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 70
+        is_incapable_of_self_care: true
+      person2:
+        age: 50
+        employment_income: 50_000
+      person3:
+        age: 5
+    tax_units:
+      tax_unit:
+        members: [person1, person2, person3]
+        filing_status: JOINT
+  output:
+    count_cdcc_eligible: 2
+    min_head_spouse_earned: 6_000
+
+- name: Both spouses floor-eligible only one spouse receives the income floor
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 70
+        is_incapable_of_self_care: true
+      person2:
+        age: 50
+        is_full_time_student: true
+      person3:
+        age: 5
+    tax_units:
+      tax_unit:
+        members: [person1, person2, person3]
+        filing_status: JOINT
+  output:
+    count_cdcc_eligible: 2
+    min_head_spouse_earned: 0
+
+- name: Both spouses floor-eligible with asymmetric earnings deems only the lower earner
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 40
+        is_full_time_student: true
+        adjusted_earnings: 5_000
+      person2:
+        age: 38
+        is_full_time_student: true
+        adjusted_earnings: 1_000
+      person3:
+        age: 5
+    tax_units:
+      tax_unit:
+        members: [person1, person2, person3]
+        filing_status: JOINT
+  output:
+    count_cdcc_eligible: 1
+    # Deem the lower earner ($1,000 -> $3,000 floor), keep the higher actual
+    # ($5,000); the lesser is $3,000. Only one spouse may be deemed.
+    min_head_spouse_earned: 3_000
diff --git a/policyengine_us/tests/policy/baseline/gov/states/dc/tax/income/dc_kccatc.yaml b/policyengine_us/tests/policy/baseline/gov/states/dc/tax/income/dc_kccatc.yaml
index 486339bc3bf..a8e6cd2ba33 100644
--- a/policyengine_us/tests/policy/baseline/gov/states/dc/tax/income/dc_kccatc.yaml
+++ b/policyengine_us/tests/policy/baseline/gov/states/dc/tax/income/dc_kccatc.yaml
@@ -17,10 +17,10 @@
     tax_units:
       tax_unit:
         members: [person1, person2, person3]
-        tax_unit_childcare_expenses: 2_000
     spm_units:
       spm_unit:
         members: [person1, person2, person3]
+        childcare_expenses: 2_000
     households:
       household:
         members: [person1, person2, person3]
@@ -47,10 +47,10 @@
     tax_units:
       tax_unit:
         members: [person1, person2, person3]
-        tax_unit_childcare_expenses: 2_000
     spm_units:
       spm_unit:
         members: [person1, person2, person3]
+        childcare_expenses: 2_000
     households:
       household:
         members: [person1, person2, person3]
@@ -77,10 +77,10 @@
     tax_units:
       tax_unit:
         members: [person1, person2, person3]
-        tax_unit_childcare_expenses: 2_000
     spm_units:
       spm_unit:
         members: [person1, person2, person3]
+        childcare_expenses: 2_000
     households:
       household:
         members: [person1, person2, person3]
@@ -107,10 +107,10 @@
     tax_units:
       tax_unit:
         members: [person1, person2, person3]
-        tax_unit_childcare_expenses: 800
     spm_units:
       spm_unit:
         members: [person1, person2, person3]
+        childcare_expenses: 800
     households:
       household:
         members: [person1, person2, person3]
@@ -136,14 +136,14 @@
         age: 3
       person4:
         is_tax_unit_dependent: true
-        age: 1        
+        age: 1
     tax_units:
       tax_unit:
         members: [person1, person2, person3, person4]
-        tax_unit_childcare_expenses: 1_600
     spm_units:
       spm_unit:
         members: [person1, person2, person3, person4]
+        childcare_expenses: 1_600
     households:
       household:
         members: [person1, person2, person3, person4]
@@ -173,13 +173,72 @@
     tax_units:
       tax_unit:
         members: [person1, person2, person3, person4]
-        tax_unit_childcare_expenses: 1_600
     spm_units:
       spm_unit:
         members: [person1, person2, person3, person4]
+        childcare_expenses: 1_600
     households:
       household:
         members: [person1, person2, person3, person4]
         state_code: DC
   output:
     dc_kccatc: 800
+
+# Regression test for the disabled-adult expense leak (review finding C1).
+# An SPM unit contains two tax units: tax_unit1 has an under-4 child AND a
+# disabled adult dependent; tax_unit2 has an under-4 child only. The $1,600 of
+# SPM childcare must be split between the two under-4 children ($800 each), so
+# each KCCATC is $800. The disabled adult is NOT a KCCATC-eligible child and
+# must not pull extra expense share into tax_unit1's child-only credit.
+# Before the fix (dc_kccatc read the disability-broadened
+# tax_unit_childcare_expenses), tax_unit1 leaked up to $1,020 and tax_unit2
+# dropped to $533.33; after the fix (child-scoped distribution) both are $800.
+- name: dc_kccatc regression - disabled adult does not inflate child-only credit
+  absolute_error_margin: 0.01
+  period: 2021
+  input:
+    people:
+      person1:
+        is_tax_unit_head: true
+        age: 35
+        employment_income: 40_000
+      person2:
+        is_tax_unit_dependent: true
+        age: 3
+      person3:
+        is_tax_unit_dependent: true
+        age: 25
+        is_incapable_of_self_care: true
+      person4:
+        is_tax_unit_head: true
+        age: 35
+        employment_income: 40_000
+      person5:
+        is_tax_unit_dependent: true
+        age: 3
+    marital_units:
+      marital_unit1:
+        members: [person1]
+      marital_unit2:
+        members: [person2]
+      marital_unit3:
+        members: [person3]
+      marital_unit4:
+        members: [person4]
+      marital_unit5:
+        members: [person5]
+    tax_units:
+      tax_unit1:
+        members: [person1, person2, person3]
+      tax_unit2:
+        members: [person4, person5]
+    spm_units:
+      spm_unit:
+        members: [person1, person2, person3, person4, person5]
+        childcare_expenses: 1_600
+    households:
+      household:
+        members: [person1, person2, person3, person4, person5]
+        state_code: DC
+  output:
+    dc_kccatc: [800, 800]
diff --git a/policyengine_us/tests/policy/baseline/gov/states/ks/tax/income/ks_cdcc.yaml b/policyengine_us/tests/policy/baseline/gov/states/ks/tax/income/ks_cdcc.yaml
index a84e622894b..48494e98d3d 100644
--- a/policyengine_us/tests/policy/baseline/gov/states/ks/tax/income/ks_cdcc.yaml
+++ b/policyengine_us/tests/policy/baseline/gov/states/ks/tax/income/ks_cdcc.yaml
@@ -5,3 +5,35 @@
     state_code: KS
   output:
     ks_cdcc: 0.25 * 1_000
+
+- name: Disabled adult dependent's care expenses count toward Kansas CDCC
+  absolute_error_margin: 0.01
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 40
+        employment_income: 40_000
+        is_tax_unit_head: true
+      person2:
+        age: 38
+        employment_income: 30_000
+      person3:
+        age: 18
+        is_incapable_of_self_care: true
+        is_tax_unit_head: false
+    spm_units:
+      spm_unit:
+        members: [person1, person2, person3]
+        spm_unit_pre_subsidy_childcare_expenses: 6_000
+    tax_units:
+      tax_unit:
+        members: [person1, person2, person3]
+    households:
+      household:
+        members: [person1, person2, person3]
+        state_code: KS
+  output:
+    tax_unit_childcare_expenses: 6_000
+    cdcc: 600
+    ks_cdcc: 300
diff --git a/policyengine_us/tests/policy/baseline/household/expense/childcare/is_dependent_care_recipient.yaml b/policyengine_us/tests/policy/baseline/household/expense/childcare/is_dependent_care_recipient.yaml
new file mode 100644
index 00000000000..c3531fe8597
--- /dev/null
+++ b/policyengine_us/tests/policy/baseline/household/expense/childcare/is_dependent_care_recipient.yaml
@@ -0,0 +1,62 @@
+- name: Child under 18 is a dependent care recipient
+  period: 2024
+  input:
+    age: 10
+    is_tax_unit_head: false
+  output:
+    is_dependent_care_recipient: true
+
+- name: Disabled adult dependent is a dependent care recipient
+  period: 2024
+  input:
+    age: 40
+    is_incapable_of_self_care: true
+    is_tax_unit_head: false
+    is_tax_unit_spouse: false
+  output:
+    is_dependent_care_recipient: true
+
+- name: Disabled adult dependent at the age 18 boundary is a recipient
+  period: 2024
+  input:
+    age: 18
+    is_incapable_of_self_care: true
+    is_tax_unit_head: false
+    is_tax_unit_spouse: false
+  output:
+    is_dependent_care_recipient: true
+
+- name: Disabled head is not a dependent care recipient
+  period: 2024
+  input:
+    age: 40
+    is_incapable_of_self_care: true
+    is_tax_unit_head: true
+  output:
+    is_dependent_care_recipient: false
+
+- name: Non-disabled non-head adult is not a dependent care recipient
+  period: 2024
+  input:
+    age: 40
+    is_incapable_of_self_care: false
+    is_tax_unit_head: false
+  output:
+    is_dependent_care_recipient: false
+
+- name: Disabled spouse assigned as tax unit head is a dependent care recipient
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 70
+        is_incapable_of_self_care: true
+      person2:
+        age: 50
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+  output:
+    is_tax_unit_head: [true, false]
+    is_tax_unit_spouse: [false, true]
+    is_dependent_care_recipient: [true, false]
diff --git a/policyengine_us/tests/policy/baseline/household/expense/childcare/pre_subsidy_care_expenses.yaml b/policyengine_us/tests/policy/baseline/household/expense/childcare/pre_subsidy_care_expenses.yaml
index 5bb9a787f1d..dc0bcb7c52d 100644
--- a/policyengine_us/tests/policy/baseline/household/expense/childcare/pre_subsidy_care_expenses.yaml
+++ b/policyengine_us/tests/policy/baseline/household/expense/childcare/pre_subsidy_care_expenses.yaml
@@ -68,3 +68,46 @@
         spm_unit_pre_subsidy_childcare_expenses: 0
   output:
     pre_subsidy_childcare_expenses: [0, 0, 0, 0, 0]
+
+- name: Disabled non-head adult receives no pre-subsidy expenses (child-scoped)
+  absolute_error_margin: 0.01
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 40
+        is_tax_unit_head: true
+      person2:
+        age: 40
+        is_incapable_of_self_care: true
+        is_tax_unit_head: false
+    spm_units:
+      spm_unit:
+        members: [person1, person2]
+        spm_unit_pre_subsidy_childcare_expenses: 6_000
+  output:
+    # Childcare subsidies are child-scoped, so a disabled adult gets nothing
+    # here; the CDCC's broader attribution lives in tax_unit_childcare_expenses.
+    pre_subsidy_childcare_expenses: [0, 0]
+
+- name: Pre-subsidy expenses go to the child, not the disabled non-head adult
+  absolute_error_margin: 0.01
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 40
+        is_tax_unit_head: true
+      person2:
+        age: 8
+        is_tax_unit_head: false
+      person3:
+        age: 40
+        is_incapable_of_self_care: true
+        is_tax_unit_head: false
+    spm_units:
+      spm_unit:
+        members: [person1, person2, person3]
+        spm_unit_pre_subsidy_childcare_expenses: 6_000
+  output:
+    pre_subsidy_childcare_expenses: [0, 6_000, 0]
diff --git a/policyengine_us/tests/policy/baseline/household/expense/childcare/tax_unit_childcare_expenses.yaml b/policyengine_us/tests/policy/baseline/household/expense/childcare/tax_unit_childcare_expenses.yaml
index 7dc082fa9df..9595302efcb 100644
--- a/policyengine_us/tests/policy/baseline/household/expense/childcare/tax_unit_childcare_expenses.yaml
+++ b/policyengine_us/tests/policy/baseline/household/expense/childcare/tax_unit_childcare_expenses.yaml
@@ -29,3 +29,45 @@
         childcare_expenses: 900
   output:
     tax_unit_childcare_expenses: [300, 600]
+
+- name: tax_unit_childcare_expenses unit test 3 (disabled non-head adult dependent)
+  absolute_error_margin: 0.01
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 40
+        is_tax_unit_head: true
+      person2:
+        age: 40
+        is_incapable_of_self_care: true
+        is_tax_unit_head: false
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+    spm_units:
+      spm_unit:
+        members: [person1, person2]
+        childcare_expenses: 6_000
+  output:
+    tax_unit_childcare_expenses: 6_000
+
+- name: tax_unit_childcare_expenses unit test 4 (disabled spouse assigned as head)
+  absolute_error_margin: 0.01
+  period: 2024
+  input:
+    people:
+      person1:
+        age: 70
+        is_incapable_of_self_care: true
+      person2:
+        age: 50
+    tax_units:
+      tax_unit:
+        members: [person1, person2]
+    spm_units:
+      spm_unit:
+        members: [person1, person2]
+        childcare_expenses: 6_000
+  output:
+    tax_unit_childcare_expenses: 6_000
diff --git a/policyengine_us/variables/gov/irs/credits/cdcc/cdcc.py b/policyengine_us/variables/gov/irs/credits/cdcc/cdcc.py
index 2edb7782635..e8aaf98e3d9 100644
--- a/policyengine_us/variables/gov/irs/credits/cdcc/cdcc.py
+++ b/policyengine_us/variables/gov/irs/credits/cdcc/cdcc.py
@@ -15,6 +15,12 @@ def formula(tax_unit, period, parameters):
         # In 2021, the CDCC was refundable
         p = parameters(period).gov.irs.credits
         if "cdcc" in p.refundable:
-            return potential
+            credit = potential
         else:
-            return min_(credit_limit, potential)
+            credit = min_(credit_limit, potential)
+        # IRC 21(e)(2): a married taxpayer may claim the credit only on a joint
+        # return. A separated taxpayer who qualifies under 21(e)(4) is treated
+        # as not married and files as head of household, not separately.
+        filing_status = tax_unit("filing_status", period)
+        separate = filing_status == filing_status.possible_values.SEPARATE
+        return where(separate, 0, credit)
diff --git a/policyengine_us/variables/gov/irs/credits/cdcc/cdcc_eligible.py b/policyengine_us/variables/gov/irs/credits/cdcc/cdcc_eligible.py
index b7f1a49b057..401cbca4c8e 100644
--- a/policyengine_us/variables/gov/irs/credits/cdcc/cdcc_eligible.py
+++ b/policyengine_us/variables/gov/irs/credits/cdcc/cdcc_eligible.py
@@ -6,15 +6,19 @@ class is_cdcc_eligible(Variable):
     entity = Person
     label = "CDCC-eligible"
     definition_period = YEAR
-    reference = "https://www.law.cornell.edu/uscode/text/26/21#b_1"
+    reference = "https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title26-section21&num=0&edition=prelim"
 
     def formula(person, period, parameters):
         age = person("age", period)
+        is_dependent = person("is_tax_unit_dependent", period)
         # Subsection A.
         max_age = parameters(period).gov.irs.credits.cdcc.eligibility.child_age
-        qualifies_by_age = age < max_age
+        qualifies_by_age = is_dependent & (age < max_age)
         # Subsection B (dependent) and C (spouse).
-        non_head = ~person("is_tax_unit_head", period)
         disabled = person("is_incapable_of_self_care", period)
-        qualifies_by_disability = non_head & disabled
+        head_or_spouse = person("is_tax_unit_head_or_spouse", period)
+        has_spouse = person.tax_unit.sum(head_or_spouse) > 1
+        qualifies_by_disability = disabled & (
+            is_dependent | (head_or_spouse & has_spouse)
+        )
         return qualifies_by_age | qualifies_by_disability
diff --git a/policyengine_us/variables/gov/irs/credits/cdcc/cdcc_income_floor_eligible.py b/policyengine_us/variables/gov/irs/credits/cdcc/cdcc_income_floor_eligible.py
new file mode 100644
index 00000000000..2f2f0757f3e
--- /dev/null
+++ b/policyengine_us/variables/gov/irs/credits/cdcc/cdcc_income_floor_eligible.py
@@ -0,0 +1,17 @@
+from policyengine_us.model_api import *
+
+
+class cdcc_income_floor_eligible(Variable):
+    value_type = bool
+    entity = Person
+    label = "Eligible for the CDCC spouse earned income floor"
+    definition_period = YEAR
+    reference = "https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title26-section21&num=0&edition=prelim"
+
+    def formula(person, period, parameters):
+        head_or_spouse = person("is_tax_unit_head_or_spouse", period)
+        has_spouse = person.tax_unit.sum(head_or_spouse) > 1
+        student_or_disabled = person("is_full_time_student", period) | person(
+            "is_incapable_of_self_care", period
+        )
+        return head_or_spouse & has_spouse & student_or_disabled
diff --git a/policyengine_us/variables/gov/irs/credits/cdcc/count_cdcc_eligible.py b/policyengine_us/variables/gov/irs/credits/cdcc/count_cdcc_eligible.py
index c5de64a0267..0274935569b 100644
--- a/policyengine_us/variables/gov/irs/credits/cdcc/count_cdcc_eligible.py
+++ b/policyengine_us/variables/gov/irs/credits/cdcc/count_cdcc_eligible.py
@@ -4,8 +4,18 @@
 class count_cdcc_eligible(Variable):
     value_type = int
     entity = TaxUnit
-    label = "CDCC-eligible children"
-    unit = USD
+    label = "CDCC qualifying individuals"
+    unit = "person"
     definition_period = YEAR
+    reference = "https://www.law.cornell.edu/uscode/text/26/21#b_1"
 
-    adds = ["is_cdcc_eligible"]
+    def formula(tax_unit, period, parameters):
+        person = tax_unit.members
+        is_eligible = person("is_cdcc_eligible", period)
+        head_or_spouse = person("is_tax_unit_head_or_spouse", period)
+        # A married couple contributes at most one qualifying individual via
+        # the spouse prong (IRC 21(b)(1)(C)): the taxpayer is never their own
+        # qualifying individual, so two incapacitated spouses count as one.
+        dependent_count = tax_unit.sum(is_eligible & ~head_or_spouse)
+        has_eligible_spouse = tax_unit.any(is_eligible & head_or_spouse)
+        return dependent_count + has_eligible_spouse
diff --git a/policyengine_us/variables/gov/irs/credits/cdcc/min_head_spouse_earned.py b/policyengine_us/variables/gov/irs/credits/cdcc/min_head_spouse_earned.py
index 34145f65f48..9c2672fb95c 100644
--- a/policyengine_us/variables/gov/irs/credits/cdcc/min_head_spouse_earned.py
+++ b/policyengine_us/variables/gov/irs/credits/cdcc/min_head_spouse_earned.py
@@ -9,7 +9,36 @@ class min_head_spouse_earned(Variable):
     definition_period = YEAR
 
     def formula(tax_unit, period, parameters):
+        p = parameters(period).gov.irs.credits.cdcc
         is_joint = tax_unit("tax_unit_is_joint", period)
-        head_earnings = tax_unit("head_earned", period)
-        spouse_earnings = tax_unit("spouse_earned", period)
-        return where(is_joint, min_(head_earnings, spouse_earnings), head_earnings)
+        person = tax_unit.members
+        is_head = person("is_tax_unit_head", period)
+        is_spouse = person("is_tax_unit_spouse", period)
+        earnings = person("adjusted_earnings", period)
+        floor_eligible = person("cdcc_income_floor_eligible", period)
+
+        head_earnings = tax_unit.sum(is_head * earnings)
+        spouse_earnings = tax_unit.sum(is_spouse * earnings)
+        head_floor_eligible = tax_unit.sum(is_head * floor_eligible) > 0
+        spouse_floor_eligible = tax_unit.sum(is_spouse * floor_eligible) > 0
+
+        # IRC section 21(d)(2): a spouse who is a student or incapable of
+        # self-care is deemed to earn at least this floor, but only one spouse
+        # may be deemed. Deem whichever eligible spouse yields the larger
+        # lesser-of-earnings, leaving the other spouse's actual earnings.
+        qualifying_individuals = tax_unit("count_cdcc_eligible", period)
+        floor = p.deemed_earned_income.calc(qualifying_individuals)
+        no_deem = min_(head_earnings, spouse_earnings)
+        deem_head = where(
+            head_floor_eligible,
+            min_(max_(head_earnings, floor), spouse_earnings),
+            0,
+        )
+        deem_spouse = where(
+            spouse_floor_eligible,
+            min_(max_(spouse_earnings, floor), head_earnings),
+            0,
+        )
+        joint_earnings = max_(no_deem, max_(deem_head, deem_spouse))
+
+        return where(is_joint, joint_earnings, tax_unit("head_earned", period))
diff --git a/policyengine_us/variables/gov/states/dc/tax/income/credits/dc_kccatc.py b/policyengine_us/variables/gov/states/dc/tax/income/credits/dc_kccatc.py
index f7cf221d777..edeb88bcc10 100644
--- a/policyengine_us/variables/gov/states/dc/tax/income/credits/dc_kccatc.py
+++ b/policyengine_us/variables/gov/states/dc/tax/income/credits/dc_kccatc.py
@@ -31,7 +31,25 @@ def formula(tax_unit, period, parameters):
         cdcc_eligible_count = tax_unit.sum(cdcc_age_eligible)
         # calculate KCCATC amount
         max_kccatc = kccatc_eligible_count * p.kccatc.max_amount
-        total_care_expenses = tax_unit("tax_unit_childcare_expenses", period)
+        # The KCCATC is a child-only credit: DC Code § 47-1806.15 limits it to
+        # dependents under age 4. Distribute the SPM unit's childcare expenses
+        # by each tax unit's share of CHILDREN, rather than reading
+        # tax_unit_childcare_expenses, which distributes by the broader
+        # dependent-care recipient set (children plus disabled dependents and
+        # spouses) used by the federal-conforming dc_cdcc. Using the child
+        # share keeps disabled-adult dependent-care dollars out of this
+        # child-only credit when a disabled adult shares an SPM unit with an
+        # eligible child.
+        spm_unit = tax_unit.spm_unit
+        spm_unit_childcare = spm_unit("childcare_expenses", period)
+        spm_unit_count_children = add(spm_unit, period, ["is_child"])
+        tax_unit_count_children = add(tax_unit, period, ["is_child"])
+        child_ratio = np.zeros_like(spm_unit_count_children)
+        child_mask = spm_unit_count_children > 0
+        child_ratio[child_mask] = (
+            tax_unit_count_children[child_mask] / spm_unit_count_children[child_mask]
+        )
+        total_care_expenses = spm_unit_childcare * child_ratio
         ratio = np.zeros_like(cdcc_eligible_count)
         mask = cdcc_eligible_count > 0
         ratio[mask] = kccatc_eligible_count[mask] / cdcc_eligible_count[mask]
diff --git a/policyengine_us/variables/household/expense/childcare/childcare_expenses.py b/policyengine_us/variables/household/expense/childcare/childcare_expenses.py
index e668a95657f..d411f17449a 100644
--- a/policyengine_us/variables/household/expense/childcare/childcare_expenses.py
+++ b/policyengine_us/variables/household/expense/childcare/childcare_expenses.py
@@ -9,8 +9,15 @@ class childcare_expenses(Variable):
     unit = USD
 
     def formula(spm_unit, period, parameters):
-        pre_subsidy_childcare_expenses = add(
-            spm_unit, period, ["pre_subsidy_childcare_expenses"]
-        )
+        # Total pre-subsidy childcare expense for the SPM unit: the larger of
+        # the SPM-level input total and the person-level sum. Re-summing the
+        # person-level distribution alone drops to $0 when the only care
+        # recipient is not a child (e.g. an incapacitated spouse with no
+        # children), which would zero out the CDCC chain downstream; falling
+        # back to the SPM total avoids that while still respecting directly-set
+        # person-level values.
+        person_sum = add(spm_unit, period, ["pre_subsidy_childcare_expenses"])
+        spm_total = spm_unit("spm_unit_pre_subsidy_childcare_expenses", period)
+        pre_subsidy = max_(person_sum, spm_total)
         subsidies = spm_unit("child_care_subsidies", period)
-        return max_(pre_subsidy_childcare_expenses - subsidies, 0)
+        return max_(pre_subsidy - subsidies, 0)
diff --git a/policyengine_us/variables/household/expense/childcare/is_dependent_care_recipient.py b/policyengine_us/variables/household/expense/childcare/is_dependent_care_recipient.py
new file mode 100644
index 00000000000..fe3438e0be0
--- /dev/null
+++ b/policyengine_us/variables/household/expense/childcare/is_dependent_care_recipient.py
@@ -0,0 +1,18 @@
+from policyengine_us.model_api import *
+
+
+class is_dependent_care_recipient(Variable):
+    value_type = bool
+    entity = Person
+    label = "Eligible to have broad childcare expenses attributed to them"
+    definition_period = YEAR
+
+    def formula(person, period, parameters):
+        is_child = person("is_child", period)
+        disabled = person("is_incapable_of_self_care", period)
+        head_or_spouse = person("is_tax_unit_head_or_spouse", period)
+        has_spouse = person.tax_unit.sum(head_or_spouse) > 1
+        dependent_or_spouse = person("is_tax_unit_dependent", period) | (
+            head_or_spouse & has_spouse
+        )
+        return is_child | (disabled & dependent_or_spouse)
diff --git a/policyengine_us/variables/household/expense/childcare/pre_subsidy_childcare_expenses.py b/policyengine_us/variables/household/expense/childcare/pre_subsidy_childcare_expenses.py
index 5a08ad777cf..dd1e4cfb46c 100644
--- a/policyengine_us/variables/household/expense/childcare/pre_subsidy_childcare_expenses.py
+++ b/policyengine_us/variables/household/expense/childcare/pre_subsidy_childcare_expenses.py
@@ -9,8 +9,10 @@ class pre_subsidy_childcare_expenses(Variable):
     unit = USD
 
     def formula(person, period, parameters):
-        # distribute the SPM unit's childcare expenses evenly across
-        # children in SPM unit's Tax units
+        # Distribute the SPM unit's childcare expenses evenly across children
+        # in the SPM unit. Childcare subsidies (CCDF/state CCAP) are for
+        # children only, so this stays child-scoped; the CDCC's broader
+        # qualifying-individual attribution lives in tax_unit_childcare_expenses.
         spm_unit = person.spm_unit
         childcare_expenses = spm_unit("spm_unit_pre_subsidy_childcare_expenses", period)
         is_child = person("is_child", period)
diff --git a/policyengine_us/variables/household/expense/childcare/tax_unit_childcare_expenses.py b/policyengine_us/variables/household/expense/childcare/tax_unit_childcare_expenses.py
index 19289bb4109..df1dbe27871 100644
--- a/policyengine_us/variables/household/expense/childcare/tax_unit_childcare_expenses.py
+++ b/policyengine_us/variables/household/expense/childcare/tax_unit_childcare_expenses.py
@@ -7,20 +7,27 @@ class tax_unit_childcare_expenses(Variable):
     label = "Childcare expenses"
     unit = USD
     definition_period = YEAR
+    reference = "https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title26-section21&num=0&edition=prelim"
 
     def formula(tax_unit, period, parameters):
-        # distribute the SPM unit's childcare expenses evenly across
-        # children in SPM unit's Tax units
+        # Distribute the SPM unit's childcare expenses across tax units in
+        # proportion to each tax unit's share of dependent-care recipients
+        # (children under 18 and disabled dependents or spouses). The CDCC
+        # narrows this to qualifying individuals downstream via cdcc_limit.
         spm_unit = tax_unit.spm_unit
         spm_unit_childcare = spm_unit("childcare_expenses", period)
-        spm_unit_count_children = add(spm_unit, period, ["is_child"])
-        tax_unit_count_children = add(tax_unit, period, ["is_child"])
+        spm_unit_count_recipients = add(
+            spm_unit, period, ["is_dependent_care_recipient"]
+        )
+        tax_unit_count_recipients = add(
+            tax_unit, period, ["is_dependent_care_recipient"]
+        )
         # avoid array divide-by-zero warning by not using where() function
         # see the following GitHub issue for more details:
         # https://github.com/PolicyEngine/policyengine-us/issues/2494
-        child_ratio = np.zeros_like(spm_unit_count_children)
-        mask = spm_unit_count_children > 0
-        child_ratio[mask] = (
-            tax_unit_count_children[mask] / spm_unit_count_children[mask]
+        recipient_ratio = np.zeros_like(spm_unit_count_recipients)
+        mask = spm_unit_count_recipients > 0
+        recipient_ratio[mask] = (
+            tax_unit_count_recipients[mask] / spm_unit_count_recipients[mask]
         )
-        return spm_unit_childcare * child_ratio
+        return spm_unit_childcare * recipient_ratio