diff --git a/changelog.d/wy-ssp-2026.added.md b/changelog.d/wy-ssp-2026.added.md
new file mode 100644
index 00000000000..5cefdcf3772
--- /dev/null
+++ b/changelog.d/wy-ssp-2026.added.md
@@ -0,0 +1 @@
+Add Wyoming's State Supplemental Payment for residents whose sole income is SSI, verified for 2026.
diff --git a/policyengine_us/parameters/gov/household/household_state_benefits.yaml b/policyengine_us/parameters/gov/household/household_state_benefits.yaml
index efec9b3ce44..dc385efe5ef 100644
--- a/policyengine_us/parameters/gov/household/household_state_benefits.yaml
+++ b/policyengine_us/parameters/gov/household/household_state_benefits.yaml
@@ -77,6 +77,8 @@ values:
     - tx_ssi_state_supplement
     # Virginia benefits
     - va_child_care_subsidies
+    # Wyoming benefits
+    - wy_ssp
     # Massachusetts benefits
     - ma_eaedc
     # DC benefits
@@ -175,6 +177,8 @@ values:
     - va_child_care_subsidies
     # West Virginia benefits
     - wv_child_care_subsidies
+    # Wyoming benefits
+    - wy_ssp
     # North Carolina benefits
     - nc_child_care_subsidies
     # South Carolina benefits
@@ -281,6 +285,8 @@ values:
     - va_child_care_subsidies
     # West Virginia benefits
     - wv_child_care_subsidies
+    # Wyoming benefits
+    - wy_ssp
     # North Carolina benefits
     - nc_child_care_subsidies
     # South Carolina benefits
@@ -388,6 +394,8 @@ values:
     - va_child_care_subsidies
     # West Virginia benefits
     - wv_child_care_subsidies
+    # Wyoming benefits
+    - wy_ssp
     # North Carolina benefits
     - nc_child_care_subsidies
     # South Carolina benefits
diff --git a/policyengine_us/parameters/gov/hud/annual_income/sources/unearned.yaml b/policyengine_us/parameters/gov/hud/annual_income/sources/unearned.yaml
index 30646eea1e9..be58eee99f2 100644
--- a/policyengine_us/parameters/gov/hud/annual_income/sources/unearned.yaml
+++ b/policyengine_us/parameters/gov/hud/annual_income/sources/unearned.yaml
@@ -21,6 +21,7 @@ values:
     - ssi
     - nj_ssp
     - pa_ssp
+    - wy_ssp
     - general_assistance
     - total_unemployment_compensation
     - child_support_received
diff --git a/policyengine_us/parameters/gov/states/wy/health/ssp/amount.yaml b/policyengine_us/parameters/gov/states/wy/health/ssp/amount.yaml
new file mode 100644
index 00000000000..06b74f11600
--- /dev/null
+++ b/policyengine_us/parameters/gov/states/wy/health/ssp/amount.yaml
@@ -0,0 +1,17 @@
+description: Wyoming provides this amount as the monthly payment under the State Supplemental Payment program.
+values:
+  2021-07-01: 20
+
+metadata:
+  unit: currency-USD
+  period: month
+  label: Wyoming SSP amount
+  reference:
+    - title: Wyoming Eligibility Online Manual M1804, State Supplemental Payments
+      href: https://ecom.wyo.gov/m1800-other-programs/m1804-state-supplemental-payments
+    - title: W.S. 42-2-103(d)
+      href: https://wyoleg.gov/statutes/compress/title42.pdf#page=7
+    - title: 2024 Wyoming Budget Act HB0001 (Enrolled Act 50), Section 2, Section 048, footnote 2
+      href: https://wyoleg.gov/2024/Enroll/HB0001.pdf#page=21
+    - title: "2026 Wyoming Budget Act SF0001 (Enrolled Act 27), Section 2, Section 048, footnote 2 #page 21-22"
+      href: https://wyoleg.gov/2026/Enroll/SF0001.pdf#page=21
diff --git a/policyengine_us/parameters/gov/usda/snap/income/sources/unearned.yaml b/policyengine_us/parameters/gov/usda/snap/income/sources/unearned.yaml
index 859029639b8..911286fbe0c 100644
--- a/policyengine_us/parameters/gov/usda/snap/income/sources/unearned.yaml
+++ b/policyengine_us/parameters/gov/usda/snap/income/sources/unearned.yaml
@@ -52,6 +52,7 @@ values:
     - sc_ssi_state_supplement
     - tx_ssi_state_supplement
     - wa_ssp
+    - wy_ssp
     # Listed elsewhere: ca_state_supplement is an SPM unit variable with no
     # person-level counterpart. policyengine-core projects a group value onto
     # every member, so listing it here would count it once per person in the
diff --git a/policyengine_us/programs.yaml b/policyengine_us/programs.yaml
index f626dd6ccc7..13c27c1be98 100644
--- a/policyengine_us/programs.yaml
+++ b/policyengine_us/programs.yaml
@@ -1117,6 +1117,16 @@ programs:
           homes, plus the institutional Supplement for Personal Needs.
           Mandatory grandfathered and essential-person supplements and
           ancillary facility subsidies are not modeled.
+      - state: WY
+        status: partial
+        name: Wyoming SSP
+        full_name: Wyoming State Supplemental Payment
+        variable: wy_ssp
+        parameter_prefix: gov.states.wy.health.ssp
+        verified_years: "2026"
+        notes: >-
+          Models the 2026 flat payment for Wyoming residents who receive SSI
+          and have no other income.
 
   - id: social_security
     name: Social Security
diff --git a/policyengine_us/tests/policy/baseline/gov/states/wy/health/ssp/integration.yaml b/policyengine_us/tests/policy/baseline/gov/states/wy/health/ssp/integration.yaml
new file mode 100644
index 00000000000..1d07b6116e3
--- /dev/null
+++ b/policyengine_us/tests/policy/baseline/gov/states/wy/health/ssp/integration.yaml
@@ -0,0 +1,40 @@
+- name: Case 1, Wyoming supplement enters state benefit and SNAP income totals.
+  period: 2026-01
+  input:
+    state_code: WY
+    age: 65
+  output:
+    wy_ssp_eligible: true
+    wy_ssp: 20
+    snap_unearned_income: 1_014
+    household_state_benefits: 20
+
+- name: Case 2, eligible couple receives twenty dollars each.
+  period: 2026-01
+  input:
+    people:
+      person1:
+        age: 65
+      person2:
+        age: 65
+    marital_units:
+      couple:
+        members: [person1, person2]
+    households:
+      household:
+        members: [person1, person2]
+        state_code: WY
+  output:
+    ssi: [745.5, 745.5]
+    wy_ssp: [20, 20]
+    household_state_benefits: 40
+
+- name: Case 3, annual Wyoming supplement counts as HUD income.
+  period: 2026
+  input:
+    state_code: WY
+    age: 65
+  output:
+    wy_ssp: 240
+    # SSI $994 * 12 = $11,928, plus the $240 supplement = $12,168.
+    hud_annual_income: 12_168
diff --git a/policyengine_us/tests/policy/baseline/gov/states/wy/health/ssp/wy_ssp.yaml b/policyengine_us/tests/policy/baseline/gov/states/wy/health/ssp/wy_ssp.yaml
new file mode 100644
index 00000000000..022a2b11f46
--- /dev/null
+++ b/policyengine_us/tests/policy/baseline/gov/states/wy/health/ssp/wy_ssp.yaml
@@ -0,0 +1,201 @@
+# Wyoming EOM M1804: $20 monthly, with SSI as the sole income source.
+- name: Case 1, aged recipient with only SSI.
+  period: 2026-01
+  input:
+    state_code: WY
+    age: 65
+  output:
+    ssi: 994
+    wy_ssp: 20
+
+- name: Case 2, income excluded from federal SSI still defeats the sole income rule.
+  period: 2026-01
+  input:
+    state_code: WY
+    age: 65
+    # $1,500 in savings, under the $2,000 SSI resource limit, earning the FDIC
+    # national savings rate of 0.37% (September 2026): $1,500 * 0.0037 = $5.55.
+    bank_account_assets: 1_500
+    taxable_interest_income: 5.55
+  output:
+    # $5.55 / 12 = $0.4625 interest a month, all absorbed by the $20 general
+    # exclusion: countable income $0, so $994 - $0 = $994.
+    ssi: 994
+    # $0.4625 > $0 is other income in the month, so the sole income rule fails.
+    wy_ssp: 0
+
+- name: Case 3, part-time earnings still defeat the sole income rule.
+  period: 2026-01
+  input:
+    state_code: WY
+    age: 65
+    # 10 hours a week at the Wyoming retail salesperson median wage of $16.50
+    # (BLS OEWS May 2025): $16.50 * 10 * 52 = $8,580 a year.
+    employment_income: 8_580
+  output:
+    # $8,580 / 12 = $715 a month; ($715 - $20 - $65) * 0.5 = $315 countable;
+    # $994 - $315 = $679.
+    ssi: 679
+    # $715 of wages is other income in the month, so the sole income rule fails.
+    wy_ssp: 0
+
+- name: Case 4, no SSI receipt.
+  period: 2026-01
+  input:
+    state_code: WY
+    age: 65
+    takes_up_ssi_if_eligible: false
+  output:
+    wy_ssp: 0
+
+- name: Case 5, outside Wyoming.
+  period: 2026-01
+  input:
+    state_code: UT
+    age: 65
+  output:
+    wy_ssp: 0
+
+- name: Case 6, institutional SSI also qualifies.
+  period: 2026-01
+  input:
+    state_code: WY
+    age: 65
+    ssi_lives_in_medical_treatment_facility: true
+    ssi_medicaid_pays_majority_of_care: true
+  output:
+    ssi: 30
+    wy_ssp: 20
+
+- name: Case 7, losses cannot offset other income for sole source eligibility.
+  period: 2026-01
+  input:
+    state_code: WY
+    age: 65
+    self_employment_income: -12_000
+    social_security_retirement: 120
+  output:
+    wy_ssp: 0
+
+- name: Case 8, a disabled child living with working parents may qualify.
+  period: 2026-01
+  absolute_error_margin: 0.01
+  input:
+    people:
+      person1:
+        age: 40
+        own_children_in_household: 1
+        # Full-time work at the Wyoming median annual wage (BLS OEWS May 2025).
+        employment_income: 50_270
+      person2:
+        age: 38
+        own_children_in_household: 1
+      person3:
+        age: 12
+        meets_ssi_disability_criteria: true
+    tax_units:
+      tax_unit:
+        members: [person1, person2, person3]
+    marital_units:
+      marital_unit:
+        members: [person1, person2]
+    households:
+      household:
+        members: [person1, person2, person3]
+        state_code: WY
+  output:
+    # Parents: $50,270 / 12 = $4,189.17 a month; ($4,189.17 - $20 - $65) * 0.5
+    # = $2,052.08; less the two-parent allocation of $1,491 = $561.08 deemed.
+    ssi_unearned_income_deemed_from_ineligible_parent: [0, 0, 561.08]
+    # Child: $561.08 - $20 general exclusion = $541.08 countable;
+    # $994 - $541.08 = $452.92. The parents are not aged, blind or disabled.
+    ssi: [0, 0, 452.92]
+    # The sole income rule reads only the child's own sources, which are $0;
+    # deemed parental income is not one of them.
+    wy_ssp: [0, 0, 20]
+
+- name: Case 9, annual total includes twelve payments.
+  period: 2026
+  input:
+    state_code: WY
+    age: 65
+  output:
+    wy_ssp: 240
+
+- name: Case 10, a self-employment loss alone is not other income.
+  period: 2026-01
+  input:
+    state_code: WY
+    age: 65
+    self_employment_income: -12_000
+  output:
+    # SSI floors earned income at $0: countable income $0, so $994 - $0 = $994.
+    ssi: 994
+    # -$12,000 / 12 = -$1,000 a month is not above $0, so no source is other
+    # income: $20.
+    wy_ssp: 20
+
+- name: Case 11, reported SSI receipt qualifies when modeled SSI is zero.
+  period: 2026-01
+  input:
+    state_code: WY
+    age: 40
+    receives_ssi: true
+  output:
+    # No disability input, so the model finds no aged, blind or disabled
+    # status and computes $0 SSI.
+    ssi: 0
+    # Reported receipt meets the SSI condition and there is no other income: $20.
+    wy_ssp: 20
+
+- name: Case 12, in an eligible couple only the spouse with other income loses the supplement.
+  period: 2026-01
+  input:
+    people:
+      person1:
+        age: 67
+        # $100 a month of Social Security retirement: $100 * 12 = $1,200 a year.
+        social_security_retirement: 1_200
+      person2:
+        age: 66
+    marital_units:
+      marital_unit:
+        members: [person1, person2]
+    households:
+      household:
+        members: [person1, person2]
+        state_code: WY
+  output:
+    # Couple: $100 - $20 general exclusion = $80 countable;
+    # ($1,491 - $80) / 2 = $705.50 each.
+    ssi: [705.5, 705.5]
+    # person1 has $100 of own income; person2's own sources are $0, so the
+    # spouse's income does not count against person2: $20.
+    wy_ssp: [0, 20]
+
+- name: Case 13, income deemed from an ineligible spouse does not defeat the sole income rule.
+  period: 2026-01
+  input:
+    people:
+      person1:
+        age: 67
+      person2:
+        age: 45
+        # 14 hours a week at the Wyoming retail salesperson median wage of
+        # $16.50 (BLS OEWS May 2025): $16.50 * 14 * 52 = $12,012 a year.
+        employment_income: 12_012
+    marital_units:
+      marital_unit:
+        members: [person1, person2]
+    households:
+      household:
+        members: [person1, person2]
+        state_code: WY
+  output:
+    # $12,012 / 12 = $1,001 a month of spouse wages, above the $497 difference
+    # between the couple and individual rates, so deeming applies:
+    # ($1,001 - $20 - $65) * 0.5 = $458 deemed; $1,491 - $458 = $1,033,
+    # capped at the $994 individual rate. person2 is not aged, blind or disabled.
+    ssi: [994, 0]
+    # person1's own sources are $0; deemed spouse income is not one of them: $20.
+    wy_ssp: [20, 0]
diff --git a/policyengine_us/variables/gov/states/wy/health/ssp/wy_ssp.py b/policyengine_us/variables/gov/states/wy/health/ssp/wy_ssp.py
new file mode 100644
index 00000000000..f7b4eeb23cd
--- /dev/null
+++ b/policyengine_us/variables/gov/states/wy/health/ssp/wy_ssp.py
@@ -0,0 +1,15 @@
+from policyengine_us.model_api import *
+
+
+class wy_ssp(Variable):
+    value_type = float
+    entity = Person
+    label = "Wyoming State Supplemental Payment"
+    definition_period = MONTH
+    unit = USD
+    defined_for = "wy_ssp_eligible"
+    reference = (
+        "https://ecom.wyo.gov/m1800-other-programs/m1804-state-supplemental-payments",
+        "https://wyoleg.gov/statutes/compress/title42.pdf#page=7",
+    )
+    adds = ["gov.states.wy.health.ssp.amount"]
diff --git a/policyengine_us/variables/gov/states/wy/health/ssp/wy_ssp_eligible.py b/policyengine_us/variables/gov/states/wy/health/ssp/wy_ssp_eligible.py
new file mode 100644
index 00000000000..ab782c831d6
--- /dev/null
+++ b/policyengine_us/variables/gov/states/wy/health/ssp/wy_ssp_eligible.py
@@ -0,0 +1,32 @@
+from policyengine_us.model_api import *
+
+
+class wy_ssp_eligible(Variable):
+    value_type = bool
+    entity = Person
+    label = "Eligible for Wyoming State Supplemental Payment"
+    definition_period = MONTH
+    defined_for = StateCode.WY
+    reference = (
+        "https://ecom.wyo.gov/m1800-other-programs/m1804-state-supplemental-payments",
+        "https://wyoleg.gov/statutes/compress/title42.pdf#page=7",
+    )
+
+    def formula(person, period, parameters):
+        receives_ssi = (person("ssi", period) > 0) | person("receives_ssi", period)
+        p = parameters(period).gov.ssa.ssi.income.sources
+        # W.S. 42-2-103(d) requires no other income in the month. The test
+        # precedes SSI exclusions, and only positive amounts count, so a loss
+        # in one source cannot offset a positive payment from another source.
+        # NOTE: noncash support and income sources absent from the federal SSI
+        # income model are not separately evaluated.
+        # NOTE: only the person's own sources count. Income deemed from a parent
+        # or an ineligible spouse, and the other spouse's income in an eligible
+        # couple, are not treated as the person's other income. The statute does
+        # not define "income", and EOM M1804 lists child cases in a parent's
+        # household (living arrangement C) among its pay-rate codes.
+        sources = list(p.earned) + list(p.unearned)
+        has_other_income = np.zeros_like(receives_ssi)
+        for source in sources:
+            has_other_income = has_other_income | (person(source, period) > 0)
+        return receives_ssi & ~has_other_income
diff --git a/policyengine_us/variables/household/income/spm_unit/spm_unit_benefits.py b/policyengine_us/variables/household/income/spm_unit/spm_unit_benefits.py
index 52d604f8842..57f160d6ebe 100644
--- a/policyengine_us/variables/household/income/spm_unit/spm_unit_benefits.py
+++ b/policyengine_us/variables/household/income/spm_unit/spm_unit_benefits.py
@@ -24,6 +24,7 @@ def formula(spm_unit, period, parameters):
             "fl_oss",
             "nj_ssp",  # New Jersey benefits
             "pa_ssp",  # Pennsylvania benefits
+            "wy_ssp",  # Wyoming benefits
             "ks_sspp",  # Kansas benefits
             "hi_oss",
             "la_oss",  # Louisiana benefits