diff --git a/changelog.d/remove-uprating-from-formula-variables.changed.md b/changelog.d/remove-uprating-from-formula-variables.changed.md
new file mode 100644
index 00000000000..1fb233348af
--- /dev/null
+++ b/changelog.d/remove-uprating-from-formula-variables.changed.md
@@ -0,0 +1 @@
+Remove redundant uprating metadata and class-level aggregation metadata from variables that already define their computation explicitly.
diff --git a/policyengine_us/data/economic_assumptions.py b/policyengine_us/data/economic_assumptions.py
index 75d03e1a791..66b4fc3eca8 100644
--- a/policyengine_us/data/economic_assumptions.py
+++ b/policyengine_us/data/economic_assumptions.py
@@ -12,6 +12,38 @@
 # is updated with new projection years, datasets will automatically
 # extend to match — no hardcoded year constant to maintain.
 CPI_U_PARAM_PATH = "gov.bls.cpi.cpi_u"
+DEFAULT_MICRODATA_UPRATING = (
+    "calibration.gov.cbo.income_by_source.adjusted_gross_income"
+)
+
+MICRODATA_UPRATING_OVERRIDES = {
+    "american_opportunity_credit": DEFAULT_MICRODATA_UPRATING,
+    "cdcc_relevant_expenses": DEFAULT_MICRODATA_UPRATING,
+    "employment_income": "calibration.gov.irs.soi.employment_income",
+    "employment_income_last_year": "calibration.gov.irs.soi.employment_income",
+    "energy_efficient_home_improvement_credit": DEFAULT_MICRODATA_UPRATING,
+    "foreign_tax_credit": DEFAULT_MICRODATA_UPRATING,
+    "interest_deduction": DEFAULT_MICRODATA_UPRATING,
+    "long_term_capital_gains": "calibration.gov.irs.soi.long_term_capital_gains",
+    "misc_deduction": DEFAULT_MICRODATA_UPRATING,
+    "person_weight": "calibration.gov.census.populations.total",
+    "pre_tax_contributions": DEFAULT_MICRODATA_UPRATING,
+    "rent": "gov.bls.cpi.cpi_u",
+    "savers_credit": DEFAULT_MICRODATA_UPRATING,
+    "self_employment_income": "calibration.gov.irs.soi.self_employment_income",
+    "self_employed_health_insurance_ald": DEFAULT_MICRODATA_UPRATING,
+    "self_employed_pension_contribution_ald": DEFAULT_MICRODATA_UPRATING,
+    "social_security": "calibration.gov.irs.soi.social_security",
+    "spm_unit_weight": "calibration.gov.census.populations.total",
+    "spm_unit_spm_threshold": DEFAULT_MICRODATA_UPRATING,
+    "state_and_local_sales_or_income_tax": DEFAULT_MICRODATA_UPRATING,
+    "sstb_self_employment_income": "calibration.gov.irs.soi.self_employment_income",
+    "taxable_pension_income": "calibration.gov.irs.soi.taxable_pension_income",
+    "taxable_unemployment_compensation": DEFAULT_MICRODATA_UPRATING,
+    "tax_unit_weight": "calibration.gov.census.populations.total",
+    "tax_exempt_pension_income": DEFAULT_MICRODATA_UPRATING,
+    "total_self_employment_income": "calibration.gov.irs.soi.self_employment_income",
+}
 
 
 def get_parameter_last_year(parameter) -> int:
@@ -100,11 +132,10 @@ def _apply_uprating(dataset: USMultiYearDataset, system=None) -> USMultiYearData
 def _apply_single_year_uprating(current, previous, system):
     """Apply multiplicative uprating from previous year to current year.
 
-    For each variable column in each entity DataFrame, looks up the
-    variable's uprating parameter path in ``system.variables``.  If the
-    variable has an uprating parameter, computes the growth factor as
-    ``param(current_year) / param(previous_year)`` and multiplies the
-    column by that factor.
+    For each variable column in each entity DataFrame, looks up its
+    dataset-extension uprating parameter path. Formula and adds/subtracts
+    variables cannot use Core variable-level uprating, so their dataset-only
+    upraters live in ``MICRODATA_UPRATING_OVERRIDES`` instead.
 
     Variables without an uprating parameter (or whose uprating parameter
     evaluates to 0 for the previous year) are left unchanged — they were
@@ -122,7 +153,9 @@ def _apply_single_year_uprating(current, previous, system):
             if col not in system.variables:
                 continue
             var = system.variables[col]
-            uprating_path = getattr(var, "uprating", None)
+            uprating_path = MICRODATA_UPRATING_OVERRIDES.get(col) or getattr(
+                var, "uprating", None
+            )
             if uprating_path is None:
                 continue
 
diff --git a/policyengine_us/tests/microsimulation/data/test_extend_single_year_dataset.py b/policyengine_us/tests/microsimulation/data/test_extend_single_year_dataset.py
index 632aa0ad2e9..16027926ac9 100644
--- a/policyengine_us/tests/microsimulation/data/test_extend_single_year_dataset.py
+++ b/policyengine_us/tests/microsimulation/data/test_extend_single_year_dataset.py
@@ -125,6 +125,30 @@ def test_given_variable_without_uprating_then_values_unchanged(
         # Then — age has no uprating, should be unchanged
         np.testing.assert_array_equal(current.person["age"].values, AGE_BASE)
 
+    def test_given_computed_variable_with_microdata_override_then_values_scaled(
+        self, base_dataset
+    ):
+        # Given
+        current = base_dataset.copy()
+        current.time_period = str(BASE_YEAR + 1)
+        previous = base_dataset
+        variables = {
+            "employment_income": MockVariable("employment_income", uprating=None)
+        }
+        system = MockSystem(
+            variables=variables,
+            parameters=build_mock_parameters(
+                {EMPLOYMENT_INCOME_UPRATING: EMPLOYMENT_INCOME_PARAM_VALUES}
+            ),
+        )
+
+        # When
+        _apply_single_year_uprating(current, previous, system)
+
+        # Then
+        expected = EMPLOYMENT_INCOME_BASE * EMPLOYMENT_INCOME_GROWTH_FACTOR_2024_TO_2025
+        np.testing.assert_allclose(current.person["employment_income"].values, expected)
+
     def test_given_household_variable_with_uprating_then_values_scaled(
         self, base_dataset, mock_system
     ):
diff --git a/policyengine_us/tests/test_system_import.py b/policyengine_us/tests/test_system_import.py
index 7cd9df70008..df73dc9ef18 100644
--- a/policyengine_us/tests/test_system_import.py
+++ b/policyengine_us/tests/test_system_import.py
@@ -36,3 +36,49 @@ def test_package_import_does_not_raise():
     import policyengine_us
 
     importlib.reload(policyengine_us)
+
+
+def test_variables_use_at_most_one_computation_mode():
+    """Variables should choose exactly one computation mode after all
+    system-level mutations, including default uprating assignment.
+    """
+    from policyengine_us.system import CountryTaxBenefitSystem
+
+    system = CountryTaxBenefitSystem()
+    conflicts = []
+    for name, variable in system.variables.items():
+        modes = []
+        if variable.formulas:
+            modes.append("formula")
+        if variable.adds is not None or variable.subtracts is not None:
+            modes.append("adds/subtracts")
+        if variable.uprating is not None:
+            modes.append("uprating")
+        if len(modes) > 1:
+            conflicts.append(f"{name}: {', '.join(modes)}")
+
+    assert conflicts == []
+
+
+def test_computed_default_uprated_variables_have_microdata_overrides():
+    """Default uprating can only be assigned to input variables at runtime.
+    Computed columns that previously received the default uprater keep that
+    behavior through microdata-only overrides.
+    """
+    from policyengine_us.data.economic_assumptions import MICRODATA_UPRATING_OVERRIDES
+    from policyengine_us.system import CountryTaxBenefitSystem
+    from policyengine_us.tools.default_uprating import INPUT_VARIABLES
+
+    system = CountryTaxBenefitSystem()
+    missing_overrides = []
+    for name in INPUT_VARIABLES:
+        variable = system.variables.get(name)
+        if variable is None:
+            continue
+        if (
+            not variable.is_input_variable()
+            and name not in MICRODATA_UPRATING_OVERRIDES
+        ):
+            missing_overrides.append(name)
+
+    assert missing_overrides == []
diff --git a/policyengine_us/tools/default_uprating.py b/policyengine_us/tools/default_uprating.py
index 8f7b3d8ba90..915dc8ddf14 100644
--- a/policyengine_us/tools/default_uprating.py
+++ b/policyengine_us/tools/default_uprating.py
@@ -98,7 +98,11 @@
 
 def add_default_uprating(system):
     for variable in system.variables.values():
-        if (variable.name in INPUT_VARIABLES) and (variable.uprating is None):
+        if (
+            (variable.name in INPUT_VARIABLES)
+            and (variable.uprating is None)
+            and variable.is_input_variable()
+        ):
             variable.uprating = (
                 "calibration.gov.cbo.income_by_source.adjusted_gross_income"
             )
diff --git a/policyengine_us/variables/gov/ssa/ss/social_security.py b/policyengine_us/variables/gov/ssa/ss/social_security.py
index 163abcabb77..003f9946929 100644
--- a/policyengine_us/variables/gov/ssa/ss/social_security.py
+++ b/policyengine_us/variables/gov/ssa/ss/social_security.py
@@ -12,4 +12,3 @@ class social_security(Variable):
         "social_security_" + i
         for i in ["dependents", "disability", "retirement", "survivors"]
     ]
-    uprating = "calibration.gov.irs.soi.social_security"
diff --git a/policyengine_us/variables/gov/states/tax/income/state_itemized_deductions.py b/policyengine_us/variables/gov/states/tax/income/state_itemized_deductions.py
index 7c7c584b279..086420bef56 100644
--- a/policyengine_us/variables/gov/states/tax/income/state_itemized_deductions.py
+++ b/policyengine_us/variables/gov/states/tax/income/state_itemized_deductions.py
@@ -7,7 +7,6 @@ class state_itemized_deductions(Variable):
     label = "State itemized deductions"
     unit = USD
     definition_period = YEAR
-    adds = "gov.states.household.state_itemized_deductions"
 
     def formula(tax_unit, period, parameters):
         # States that adopt the federal itemized deductions
diff --git a/policyengine_us/variables/gov/states/tax/income/taxsim_state_agi.py b/policyengine_us/variables/gov/states/tax/income/taxsim_state_agi.py
index b91941ca0c3..dcd31c2df2d 100644
--- a/policyengine_us/variables/gov/states/tax/income/taxsim_state_agi.py
+++ b/policyengine_us/variables/gov/states/tax/income/taxsim_state_agi.py
@@ -7,7 +7,6 @@ class taxsim_state_agi(Variable):
     label = "State adjusted gross income"
     unit = USD
     definition_period = YEAR
-    adds = "gov.states.household.state_agis"
 
     def formula(tax_unit, period, parameters):
         # States that adopt the federal AGI
diff --git a/policyengine_us/variables/household/demographic/weights/person_weight.py b/policyengine_us/variables/household/demographic/weights/person_weight.py
index 27553ab00ac..fc465f66c1d 100644
--- a/policyengine_us/variables/household/demographic/weights/person_weight.py
+++ b/policyengine_us/variables/household/demographic/weights/person_weight.py
@@ -6,7 +6,6 @@ class person_weight(Variable):
     entity = Person
     label = "Person weight"
     definition_period = YEAR
-    uprating = "calibration.gov.census.populations.total"
 
     def formula(person, period, parameters):
         return person.household("household_weight", period)
diff --git a/policyengine_us/variables/household/demographic/weights/spm_unit_weight.py b/policyengine_us/variables/household/demographic/weights/spm_unit_weight.py
index 5d8ed9aba82..7bd9e182198 100644
--- a/policyengine_us/variables/household/demographic/weights/spm_unit_weight.py
+++ b/policyengine_us/variables/household/demographic/weights/spm_unit_weight.py
@@ -6,7 +6,6 @@ class spm_unit_weight(Variable):
     entity = SPMUnit
     label = "SPM unit weight"
     definition_period = YEAR
-    uprating = "calibration.gov.census.populations.total"
 
     def formula(spm_unit, period, parameters):
         # Use household weights if not provided
diff --git a/policyengine_us/variables/household/demographic/weights/tax_unit_weight.py b/policyengine_us/variables/household/demographic/weights/tax_unit_weight.py
index 01c5e4e2536..8c471fb8fe8 100644
--- a/policyengine_us/variables/household/demographic/weights/tax_unit_weight.py
+++ b/policyengine_us/variables/household/demographic/weights/tax_unit_weight.py
@@ -6,7 +6,6 @@ class tax_unit_weight(Variable):
     entity = TaxUnit
     label = "Tax unit weight"
     definition_period = YEAR
-    uprating = "calibration.gov.census.populations.total"
 
     def formula(tax_unit, period, parameters):
         return tax_unit.household("household_weight", period)
diff --git a/policyengine_us/variables/household/expense/housing/rent.py b/policyengine_us/variables/household/expense/housing/rent.py
index 47d560e14a4..081a286054d 100644
--- a/policyengine_us/variables/household/expense/housing/rent.py
+++ b/policyengine_us/variables/household/expense/housing/rent.py
@@ -7,7 +7,6 @@ class rent(Variable):
     label = "Rent"
     unit = USD
     definition_period = YEAR
-    uprating = "gov.bls.cpi.cpi_u"
 
     def formula(person, period, parameters):
         pre_subsidy_rent = person("pre_subsidy_rent", period)
diff --git a/policyengine_us/variables/household/income/person/capital_gains/long_term_capital_gains.py b/policyengine_us/variables/household/income/person/capital_gains/long_term_capital_gains.py
index aab51871699..86d1e3e9d59 100644
--- a/policyengine_us/variables/household/income/person/capital_gains/long_term_capital_gains.py
+++ b/policyengine_us/variables/household/income/person/capital_gains/long_term_capital_gains.py
@@ -12,7 +12,6 @@ class long_term_capital_gains(Variable):
         title="26 U.S. Code § 1222(3)",
         href="https://www.law.cornell.edu/uscode/text/26/1222#3",
     )
-    uprating = "calibration.gov.irs.soi.long_term_capital_gains"
     adds = [
         "long_term_capital_gains_before_response",
         "capital_gains_behavioral_response",
diff --git a/policyengine_us/variables/household/income/person/employment_income_last_year.py b/policyengine_us/variables/household/income/person/employment_income_last_year.py
index 6e9d21ed647..4220cb92231 100644
--- a/policyengine_us/variables/household/income/person/employment_income_last_year.py
+++ b/policyengine_us/variables/household/income/person/employment_income_last_year.py
@@ -8,7 +8,6 @@ class employment_income_last_year(Variable):
     documentation = "Wages and salaries in prior year, including tips and commissions."
     unit = USD
     definition_period = YEAR
-    uprating = "calibration.gov.irs.soi.employment_income"
 
     def formula_2024(person, period, parameters):
         employment_income_target = parameters.calibration.gov.irs.soi.employment_income
diff --git a/policyengine_us/variables/household/income/person/retirement/taxable_pension_income.py b/policyengine_us/variables/household/income/person/retirement/taxable_pension_income.py
index b1f36a0d6fe..ea9d48c12ca 100644
--- a/policyengine_us/variables/household/income/person/retirement/taxable_pension_income.py
+++ b/policyengine_us/variables/household/income/person/retirement/taxable_pension_income.py
@@ -7,6 +7,5 @@ class taxable_pension_income(Variable):
     label = "taxable pension income"
     unit = USD
     definition_period = YEAR
-    uprating = "calibration.gov.irs.soi.taxable_pension_income"
 
     adds = ["taxable_public_pension_income", "taxable_private_pension_income"]
diff --git a/policyengine_us/variables/household/income/person/self_employment/total_self_employment_income.py b/policyengine_us/variables/household/income/person/self_employment/total_self_employment_income.py
index c5699055e0d..6851e3b795e 100644
--- a/policyengine_us/variables/household/income/person/self_employment/total_self_employment_income.py
+++ b/policyengine_us/variables/household/income/person/self_employment/total_self_employment_income.py
@@ -13,4 +13,3 @@ class total_self_employment_income(Variable):
     definition_period = YEAR
     adds = ["self_employment_income", "sstb_self_employment_income"]
     reference = "https://www.law.cornell.edu/uscode/text/26/1402#a"
-    uprating = "calibration.gov.irs.soi.self_employment_income"
diff --git a/policyengine_us/variables/input/employment_income.py b/policyengine_us/variables/input/employment_income.py
index feab9b621d5..499dd2c3ab3 100644
--- a/policyengine_us/variables/input/employment_income.py
+++ b/policyengine_us/variables/input/employment_income.py
@@ -13,4 +13,3 @@ class employment_income(Variable):
         "employment_income_behavioral_response",
     ]
     reference = "https://www.law.cornell.edu/uscode/text/26/3401#a"
-    uprating = "calibration.gov.irs.soi.employment_income"
diff --git a/policyengine_us/variables/input/self_employment_income.py b/policyengine_us/variables/input/self_employment_income.py
index 8f4db220852..708d7fc6b0f 100644
--- a/policyengine_us/variables/input/self_employment_income.py
+++ b/policyengine_us/variables/input/self_employment_income.py
@@ -13,4 +13,3 @@ class self_employment_income(Variable):
         "self_employment_income_behavioral_response",
     ]
     reference = "https://www.law.cornell.edu/uscode/text/26/1402#a"
-    uprating = "calibration.gov.irs.soi.self_employment_income"
diff --git a/policyengine_us/variables/input/sstb_self_employment_income.py b/policyengine_us/variables/input/sstb_self_employment_income.py
index c0cab37c3ad..f135d901cf0 100644
--- a/policyengine_us/variables/input/sstb_self_employment_income.py
+++ b/policyengine_us/variables/input/sstb_self_employment_income.py
@@ -23,4 +23,3 @@ class sstb_self_employment_income(Variable):
         "sstb_self_employment_income_before_lsr",
         "sstb_self_employment_income_behavioral_response",
     ]
-    uprating = "calibration.gov.irs.soi.self_employment_income"