# State rebate attribution

PolicyEngine attributes one-time state rebates to the tax year whose return
determines eligibility and amount, even when checks arrive in a later
calendar year. Rebates included in state credit totals reduce
`state_income_tax` and increase household net income in that eligibility year.
This attribution convention does not describe the payment calendar. Some
standalone rebate formulas can calculate an amount after the rebate ends;
use the dated credit total to establish whether that amount enters tax or net
income. Do not add back every positive raw rebate column in every year.
Massachusetts premium pay is also modeled through state refundable credits.
A payment modeled solely as a benefit would affect household net income
without reducing state income tax.

For comparison, restore only the rebate amounts that actually reduced that
year's reported state tax, including liability limits on nonrefundable
credits. Ordinary recurring refundable credits remain part of liability.
`state_income_tax_before_refundable_credits` removes those ordinary credits
too, so it is not a pre-rebate liability measure. Colorado Cash Back and the
residual TABOR sales tax refund are separate mechanisms; count each only
through its stated aggregation path and eligibility year.

## Inventory

The years below are eligibility tax years in which a qualifying household can
receive a nonzero contribution to the state's credit total. `R` denotes the
state's refundable-credit total; `N` denotes its nonrefundable-credit total.
Every listed payment enters state tax through credits, including Colorado Cash
Back and Massachusetts premium pay. None is a second, direct household benefit
payment. Refundable totals enter both state tax and household refundable credits;
nonrefundable totals reduce tax before refundable credits.

| Rebate and variable(s) | Eligibility years included in state credit totals | Payment year | Aggregation and amount gate |
|---|---|---|---|
| Colorado residual TABOR sales tax refund: `co_sales_tax_refund`; helpers `co_sales_tax_refund_eligible`, `co_sales_tax_refund_person_eligible` | 2015, 2021–2025, and 2027 onward under current parameters; zero in 2016–2020 and 2026 | Following the eligibility return | R: `co_refundable_credits`. The formula multiplies the eligible-filer amount by `sales_tax_refund.in_effect`. This recurring residual mechanism is separate from Colorado Cash Back. |
| Colorado Cash Back: `co_tabor_cash_back` | 2021 only | 2022 | R: `co_refundable_credits`, removed from the dated list in 2022. The amount is zero outside 2021. |
| Illinois income and property rebates: `il_income_tax_rebate`, `il_property_tax_rebate`; helpers `il_income_tax_rebate_eligible`, `il_property_tax_rebate_eligible` | 2021 only | 2022 | R: `il_refundable_credits`, removed from the dated list in 2022. Income-rebate amounts and the property-rebate cap are zero before 2021. |
| New York inflation refund: `ny_inflation_refund_credit` | 2023 only | 2025 | R: `ny_refundable_credits`. The variable has a 2023 formula and resets to zero in 2024. |
| Virginia rebates: `va_rebate` | 2021, 2022, and 2024 | 2022, 2023, and 2025, respectively | N: `va_non_refundable_credits`, limited by available tax liability. Amounts are zero in other years. |
| Georgia surplus refund: `ga_surplus_tax_rebate` | 2021 only | Later than the eligibility return | R: `ga_refundable_credits`. The O.C.G.A. 48-7-20.2 refund is capped at income tax before credits; the amount is zero outside 2021. |
| Arizona Families Tax Rebate: `az_families_tax_rebate` | 2021 only | 2023 | R: `az_refundable_credits`. The dated list excludes it before 2021 and removes it in 2022, even when its standalone formula returns a positive amount. |
| New Mexico rebates: `nm_2021_income_rebate`, `nm_additional_2021_income_rebate`, `nm_supplemental_2021_income_rebate` | 2021 only | Enacted in 2022 and 2023 for the 2021 return | R: `nm_refundable_credits`, removed from the dated list in 2022. All filing-status amount branches are zero before 2021. The supplemental variable combines two payments. |
| Connecticut child rebate: `ct_child_tax_rebate` | 2021 only | 2022 | R: `ct_refundable_credits`. The amount and child cap are zero outside 2021. The model assumes full take-up and uses 2021 residence as a proxy for domicile at application in 2022. |
| Rhode Island child rebate: `ri_child_tax_rebate`; helper `ri_child_tax_rebate_eligible` | 2021 only | 2022 | R: `ri_refundable_credits`. The amount is zero outside 2021; a true eligibility flag in another year does not imply a payment. |
| Hawaii Act 115 refund: `hi_act_115_rebate` | 2021 only | 2022 | R: `hi_refundable_credits`, removed from the dated list in 2022. Both filing-status schedules are zero before 2021. |
| Maine relief payment: `me_relief_rebate`; helper `me_relief_rebate_eligible` | 2021 only | 2022 | R: `me_refundable_credits`. The $850 amount is zero outside 2021; the eligibility flag alone does not imply a payment. |
| Massachusetts Chapter 62F refund: `ma_taxpayer_refund_rebate` | 2021 only | 2022 | R: `ma_refundable_credits`. Only the 2021 dated list includes it, although its standalone rate persists. |
| Montana HB 192 income tax rebate: `mt_income_tax_rebate` (person level); supporting `mt_income_tax_before_2021_rebate` | 2021 only | 2023 | R: `mt_refundable_credits` adds person-level amounts directly, outside the parameter list. The rebate is liability-capped once per return and zero outside 2021. The separate-versus-joint filing election is determined before the rebate by assumption. |
| South Carolina rebate: `sc_2022_rebate` | 2021 only | 2022 | N: `sc_non_refundable_credits`. The rebate is capped at $800 and eligible liability; the amount is zero outside 2021. |
| Massachusetts essential employee premium pay: `ma_covid_19_essential_employee_premium_pay_program` (person level); input `claimed_ma_covid_19_essential_employee_premium_pay_program_2020` | 2020 and 2021 only | Both modeled rounds paid in 2022 | R: `ma_refundable_credits`. The two $500 rounds use 2020 and 2021 earnings, respectively. The amount is zero before 2020 and from 2022. Set the prior-recipient input in 2021 to exclude a first-round recipient from the second round. The later $250 third round is outside this inventory's coverage. |

The model's first modeled year is 2015. Colorado's 2015 amounts follow the
2015 DR 0104 table (Form 104, line 46); the refund is zero in 2016–2020, when it
was not in effect. Colorado's 2027–2029 tiers are the LCS September 2026
forecast's projections, not published DR 0104 tables, and they stand in until
the State Controller certifies each fiscal year's surplus and CDOR publishes
that year's tiers in the DR 0104.

## Standalone amounts and comparison measures

Illinois's two rebates, New Mexico's three rebates, and Hawaii's Act 115 refund
can return positive standalone amounts after 2021 because their schedules
persist. Their historical guards make the amounts zero before 2021, and the
dated credit totals exclude them after 2021. Arizona and Massachusetts Chapter
62F also have standalone formulas that can remain positive in other years,
while their dated credit lists include them only in 2021.

Maine, Montana, South Carolina, Colorado Cash Back, Connecticut, Rhode Island,
Georgia, New York, and Massachusetts premium pay have amount or formula end
dates. Eligibility helpers and positive standalone amounts are not substitutes
for checking the dated aggregation path and applied liability cap.

The [TAXSIM validation comparison](taxsim.md#how-agreement-is-measured) includes
a rebate-adjusted metric. Its limitations and each program's aggregation path
matter when reconciling that metric with the reported state income tax.