diff --git a/changelog.d/pure-leaf-inputs.md b/changelog.d/pure-leaf-inputs.md
new file mode 100644
index 00000000000..da130bc9f72
--- /dev/null
+++ b/changelog.d/pure-leaf-inputs.md
@@ -0,0 +1 @@
+- Removed non-geographic guards from input variables so they remain pure data inputs, and added checks preventing input variables from using formulas, adds, subtracts, or non-geographic `defined_for` gates.
diff --git a/policyengine_us/tests/core/test_input_variable_definitions.py b/policyengine_us/tests/core/test_input_variable_definitions.py
new file mode 100644
index 00000000000..02883e15b7c
--- /dev/null
+++ b/policyengine_us/tests/core/test_input_variable_definitions.py
@@ -0,0 +1,63 @@
+from policyengine_us import CountryTaxBenefitSystem
+from policyengine_us.model_api import STATES
+
+
+def _is_geographic_defined_for(defined_for: str) -> bool:
+    return defined_for in STATES or defined_for.startswith("in_")
+
+
+def _state_prefix(name):
+    for state in STATES:
+        if name.startswith(f"{state.lower()}_"):
+            return state
+    return None
+
+
+def test_input_variables_do_not_use_non_geographic_defined_for():
+    system = CountryTaxBenefitSystem()
+
+    invalid = {
+        name: variable.defined_for
+        for name, variable in system.variables.items()
+        if variable.is_input_variable()
+        and variable.defined_for is not None
+        and not _is_geographic_defined_for(variable.defined_for)
+    }
+
+    assert invalid == {}
+
+
+def test_input_variables_do_not_use_formulas_adds_or_subtracts():
+    system = CountryTaxBenefitSystem()
+
+    invalid = {
+        name: {
+            "formulas": bool(getattr(variable, "formulas", None)),
+            "adds": bool(getattr(variable, "adds", None)),
+            "subtracts": bool(getattr(variable, "subtracts", None)),
+        }
+        for name, variable in system.variables.items()
+        if variable.is_input_variable()
+        and (
+            getattr(variable, "formulas", None)
+            or getattr(variable, "adds", None)
+            or getattr(variable, "subtracts", None)
+        )
+    }
+
+    assert invalid == {}
+
+
+def test_state_input_variables_match_state_defined_for():
+    system = CountryTaxBenefitSystem()
+
+    invalid = {
+        name: variable.defined_for
+        for name, variable in system.variables.items()
+        if variable.is_input_variable()
+        and _state_prefix(name) is not None
+        and variable.defined_for in STATES
+        and variable.defined_for != _state_prefix(name)
+    }
+
+    assert invalid == {}
diff --git a/policyengine_us/tests/policy/baseline/gov/states/ny/nyserda/drive_clean_rebate.yaml b/policyengine_us/tests/policy/baseline/gov/states/ny/nyserda/drive_clean_rebate.yaml
index f9f0d07fd13..828be8b2af2 100644
--- a/policyengine_us/tests/policy/baseline/gov/states/ny/nyserda/drive_clean_rebate.yaml
+++ b/policyengine_us/tests/policy/baseline/gov/states/ny/nyserda/drive_clean_rebate.yaml
@@ -2,6 +2,7 @@
   period: 2022
   input:
     state_code: NY
+    ny_drive_clean_purchased_qualifying_vehicle: true
     ny_drive_clean_vehicle_cost: 30_000
     ny_drive_clean_vehicle_electric_range: 5
   output:
@@ -11,6 +12,7 @@
   period: 2022
   input:
     state_code: NY
+    ny_drive_clean_purchased_qualifying_vehicle: true
     ny_drive_clean_vehicle_cost: 30_000
     ny_drive_clean_vehicle_electric_range: 40
   output:
@@ -20,6 +22,7 @@
   period: 2022
   input:
     state_code: NY
+    ny_drive_clean_purchased_qualifying_vehicle: true
     ny_drive_clean_vehicle_cost: 30_000
     ny_drive_clean_vehicle_electric_range: 200
   output:
@@ -29,6 +32,7 @@
   period: 2022
   input:
     state_code: NY
+    ny_drive_clean_purchased_qualifying_vehicle: true
     ny_drive_clean_vehicle_cost: 50_000
     ny_drive_clean_vehicle_electric_range: 40
   output:
@@ -38,6 +42,7 @@
   period: 2022
   input:
     state_code: NY
+    ny_drive_clean_purchased_qualifying_vehicle: true
     ny_drive_clean_vehicle_cost: 50_000
     ny_drive_clean_vehicle_electric_range: 200
   output:
@@ -47,6 +52,7 @@
   period: 2019
   input:
     state_code: NY
+    ny_drive_clean_purchased_qualifying_vehicle: true
     ny_drive_clean_vehicle_cost: 42_000
     ny_drive_clean_vehicle_electric_range: 10
   output:
@@ -56,6 +62,7 @@
   period: 2019
   input:
     state_code: NY
+    ny_drive_clean_purchased_qualifying_vehicle: true
     ny_drive_clean_vehicle_cost: 42_000
     ny_drive_clean_vehicle_electric_range: 20
   output:
@@ -65,6 +72,7 @@
   period: 2019
   input:
     state_code: NY
+    ny_drive_clean_purchased_qualifying_vehicle: true
     ny_drive_clean_vehicle_cost: 42_000
     ny_drive_clean_vehicle_electric_range: 40
   output:
@@ -74,6 +82,7 @@
   period: 2019
   input:
     state_code: NY
+    ny_drive_clean_purchased_qualifying_vehicle: true
     ny_drive_clean_vehicle_cost: 42_000
     ny_drive_clean_vehicle_electric_range: 120
   output:
@@ -83,6 +92,7 @@
   period: 2019
   input:
     state_code: NY
+    ny_drive_clean_purchased_qualifying_vehicle: true
     ny_drive_clean_vehicle_cost: 70_000
     ny_drive_clean_vehicle_electric_range: 20
   output:
@@ -92,6 +102,7 @@
   period: 2019
   input:
     state_code: NY
+    ny_drive_clean_purchased_qualifying_vehicle: true
     ny_drive_clean_vehicle_cost: 70_000
     ny_drive_clean_vehicle_electric_range: 40
   output:
@@ -101,7 +112,18 @@
   period: 2019
   input:
     state_code: NY
+    ny_drive_clean_purchased_qualifying_vehicle: true
     ny_drive_clean_vehicle_cost: 70_000
     ny_drive_clean_vehicle_electric_range: 200
   output:
     ny_drive_clean_rebate: 500
+
+- name: No qualifying purchase
+  period: 2022
+  input:
+    state_code: NY
+    ny_drive_clean_purchased_qualifying_vehicle: false
+    ny_drive_clean_vehicle_cost: 30_000
+    ny_drive_clean_vehicle_electric_range: 200
+  output:
+    ny_drive_clean_rebate: 0
diff --git a/policyengine_us/variables/gov/hhs/medicare/costs/medicare_enrolled.py b/policyengine_us/variables/gov/hhs/medicare/costs/medicare_enrolled.py
index 9792cce961d..3b715488595 100644
--- a/policyengine_us/variables/gov/hhs/medicare/costs/medicare_enrolled.py
+++ b/policyengine_us/variables/gov/hhs/medicare/costs/medicare_enrolled.py
@@ -8,5 +8,4 @@ class medicare_enrolled(Variable):
     documentation = "Whether the person is enrolled in Medicare (Part A and/or Part B)"
     definition_period = YEAR
     reference = "https://www.cms.gov/medicare"
-    defined_for = "is_medicare_eligible"
-    default_value = True  # Most Medicare-eligible people are enrolled
+    default_value = False
diff --git a/policyengine_us/variables/gov/local/ca/la/general_relief/eligibility/la_general_relief_disability_eligible.py b/policyengine_us/variables/gov/local/ca/la/general_relief/eligibility/la_general_relief_disability_eligible.py
index 5f7fbbfcf94..8f530d26482 100644
--- a/policyengine_us/variables/gov/local/ca/la/general_relief/eligibility/la_general_relief_disability_eligible.py
+++ b/policyengine_us/variables/gov/local/ca/la/general_relief/eligibility/la_general_relief_disability_eligible.py
@@ -8,5 +8,4 @@ class la_general_relief_disability_eligible(Variable):
     label = "Eligible for the Los Angeles County General Relief based on the disability requirements"
     # Person has to be disabled AND unable to work
     # which is curently not implemented
-    defined_for = "is_disabled"
     reference = "https://drive.google.com/file/d/1Oc7UuRFxJj-eDwTeox92PtmRVGnG9RjW/view?usp=sharing"
diff --git a/policyengine_us/variables/gov/local/ca/la/general_relief/housing_subsidy/eligibility/la_general_relief_housing_subsidy_program_eligible.py b/policyengine_us/variables/gov/local/ca/la/general_relief/housing_subsidy/eligibility/la_general_relief_housing_subsidy_program_eligible.py
index 24857e01085..37ab0abe7de 100644
--- a/policyengine_us/variables/gov/local/ca/la/general_relief/housing_subsidy/eligibility/la_general_relief_housing_subsidy_program_eligible.py
+++ b/policyengine_us/variables/gov/local/ca/la/general_relief/housing_subsidy/eligibility/la_general_relief_housing_subsidy_program_eligible.py
@@ -7,5 +7,4 @@ class la_general_relief_housing_subsidy_program_eligible(Variable):
     label = "Eligible for the Los Angeles County General Relief Housing Subsidy based on the program eligibility"
     definition_period = YEAR
     # Person has to be a resident of LA County
-    defined_for = "la_general_relief_eligible"
     reference = "https://dpss.lacounty.gov/en/cash/gr/housing.html"
diff --git a/policyengine_us/variables/gov/states/il/dhs/aabd/il_aabd_institutional_status.py b/policyengine_us/variables/gov/states/il/dhs/aabd/il_aabd_institutional_status.py
index 3e28d6ec490..1ee62d9ac2d 100644
--- a/policyengine_us/variables/gov/states/il/dhs/aabd/il_aabd_institutional_status.py
+++ b/policyengine_us/variables/gov/states/il/dhs/aabd/il_aabd_institutional_status.py
@@ -21,5 +21,5 @@ class il_aabd_institutional_status(Variable):
     default_value = IllinoisAABDInstitutionalStatus.NONE
     definition_period = MONTH
     label = "Illinois AABD Institutional Status"
-    defined_for = StateCode.MA
+    defined_for = StateCode.IL
     reference = "https://www.law.cornell.edu/regulations/illinois/Ill-Admin-Code-tit-89-SS-113.70"
diff --git a/policyengine_us/variables/gov/states/ny/nyserda/drive_clean/ny_drive_clean_rebate.py b/policyengine_us/variables/gov/states/ny/nyserda/drive_clean/ny_drive_clean_rebate.py
index 6ecda1ca3a8..f70d9241133 100644
--- a/policyengine_us/variables/gov/states/ny/nyserda/drive_clean/ny_drive_clean_rebate.py
+++ b/policyengine_us/variables/gov/states/ny/nyserda/drive_clean/ny_drive_clean_rebate.py
@@ -12,6 +12,9 @@ class ny_drive_clean_rebate(Variable):
 
     def formula(tax_unit, period, parameters):
         p = parameters(period).gov.states.ny.nyserda.drive_clean
+        purchased_qualifying_vehicle = tax_unit(
+            "ny_drive_clean_purchased_qualifying_vehicle", period
+        )
         # Calculate vehicle all-electric range
         vehicle_range = tax_unit("ny_drive_clean_vehicle_electric_range", period)
         # Calculate vehicle price
@@ -23,7 +26,7 @@ def formula(tax_unit, period, parameters):
         vehicle_over_msrp_threshold = vehicle_cost >= p.flat_rebate.msrp_threshold
         # If the vehicle is more expensive than the MSRP treshold, the filer
         # receives the flat rebate, otherwise they receive the range-based rebate
-        return where(
+        return purchased_qualifying_vehicle * where(
             vehicle_over_msrp_threshold,
             p.flat_rebate.amount,
             rebate_amount_based_on_range,
diff --git a/policyengine_us/variables/gov/states/ny/nyserda/drive_clean/ny_drive_clean_vehicle_cost.py b/policyengine_us/variables/gov/states/ny/nyserda/drive_clean/ny_drive_clean_vehicle_cost.py
index 0c5e63820fc..312bcec3031 100644
--- a/policyengine_us/variables/gov/states/ny/nyserda/drive_clean/ny_drive_clean_vehicle_cost.py
+++ b/policyengine_us/variables/gov/states/ny/nyserda/drive_clean/ny_drive_clean_vehicle_cost.py
@@ -8,4 +8,3 @@ class ny_drive_clean_vehicle_cost(Variable):
     unit = USD
     definition_period = YEAR
     reference = "https://www.nyserda.ny.gov/-/media/Project/Nyserda/Files/Programs/Drive-Clean-NY/implementation-manual.pdf#page=8"
-    defined_for = "ny_drive_clean_purchased_qualifying_vehicle"
diff --git a/policyengine_us/variables/gov/states/sc/tax/income/credits/college_tuition/sc_tuition_credit.py b/policyengine_us/variables/gov/states/sc/tax/income/credits/college_tuition/sc_tuition_credit.py
index d43d33a7f12..e1beb343dcc 100644
--- a/policyengine_us/variables/gov/states/sc/tax/income/credits/college_tuition/sc_tuition_credit.py
+++ b/policyengine_us/variables/gov/states/sc/tax/income/credits/college_tuition/sc_tuition_credit.py
@@ -5,7 +5,6 @@ class sc_tuition_credit(Variable):
     value_type = float
     entity = Person
     label = "South Carolina Tuition Credit"
-    defined_for = "sc_tuition_credit_eligible"
     unit = USD
     definition_period = YEAR
     reference = (
diff --git a/policyengine_us/variables/household/demographic/person/current_pregnancy_month.py b/policyengine_us/variables/household/demographic/person/current_pregnancy_month.py
index b3d40104fd3..71328147b41 100644
--- a/policyengine_us/variables/household/demographic/person/current_pregnancy_month.py
+++ b/policyengine_us/variables/household/demographic/person/current_pregnancy_month.py
@@ -6,4 +6,3 @@ class current_pregnancy_month(Variable):
     entity = Person
     label = "Current pregnancy month"
     definition_period = MONTH
-    defined_for = "is_pregnant"
diff --git a/policyengine_us/variables/household/demographic/person/is_in_foster_care_group_home.py b/policyengine_us/variables/household/demographic/person/is_in_foster_care_group_home.py
index d1391be5ee2..50f36e3c406 100644
--- a/policyengine_us/variables/household/demographic/person/is_in_foster_care_group_home.py
+++ b/policyengine_us/variables/household/demographic/person/is_in_foster_care_group_home.py
@@ -7,4 +7,3 @@ class is_in_foster_care_group_home(Variable):
     label = "Person is currently in a qualifying foster care group home"
     definition_period = MONTH
     default_value = False
-    defined_for = "is_in_foster_care"
diff --git a/policyengine_us/variables/household/demographic/person/retired_from_federal_government.py b/policyengine_us/variables/household/demographic/person/retired_from_federal_government.py
index 9b7c8618b0c..8f189c47536 100644
--- a/policyengine_us/variables/household/demographic/person/retired_from_federal_government.py
+++ b/policyengine_us/variables/household/demographic/person/retired_from_federal_government.py
@@ -6,5 +6,4 @@ class retired_from_federal_government(Variable):
     entity = Person
     label = "Retired from Federal Government"
     definition_period = YEAR
-    defined_for = "is_retired"
     default_value = False