State support
2026 state coverage
51 of 51 US jurisdictions are live. Every state and DC has a transparent launch status, with documented limitations where applicable.
| State | Launch status | Calculation status | Limitations | Source year | Next action |
|---|---|---|---|---|---|
| Alabama (AL) | Limited | partial_support / limited | AL_STANDARD_DEDUCTION_PHASEOUT_UNSUPPORTED; AL_DEPENDENT_EXEMPTION_UNSUPPORTED | 2026 | Add phase-out and dependent exemption only when source-backed and approved. |
| Alaska (AK) | No income tax | official_2026 / supported | None | 2026 | Keep source evidence current. |
| Arizona (AZ) | Limited | partial_support / limited | AZ_A4_SCOPE_LIMITED | 2026 | Add additional Arizona-specific fields only when source-backed. |
| Arkansas (AR) | Limited | partial_support / limited | AR_LOW_INCOME_CREDIT_UNSUPPORTED; AR_EXEMPTION_COUNT_UNSUPPORTED | 2026 | Add low-income replacement logic and exemption-count input only when source-backed. |
| California (CA) | Limited | prior_year_used / limited | PRIOR_YEAR_STATE_TABLE | 2026 | Build dedicated CA Method B strategy. |
| Colorado (CO) | Limited | partial_support / limited | CO_DR0004_SCOPE_LIMITED | 2026 | Add DR 0004 input model if approved. |
| Connecticut (CT) | Limited | partial_support / limited | CT_PHASE_OUT_RECAPTURE_UNSUPPORTED | 2026 | Add phase-out recapture and CT-W4 code adjustments when source-backed and approved. |
| Delaware (DE) | Limited | partial_support / limited | DE_EXACT_COMPUTATION_SCOPE_LIMITED | 2026 | Add certificate variants only after official form semantics are modeled. |
| Florida (FL) | No income tax | official_2026 / supported | None | 2026 | Keep source evidence current. |
| Georgia (GA) | Supported | official_2026 / supported | None | 2026 | Keep tests current. |
| Hawaii (HI) | Supported | official_2026 / supported | None | 2026 | Keep tests current. |
| Idaho (ID) | Supported | official_2026 / supported | None | 2026 | Keep tests current. |
| Illinois (IL) | Limited | partial_support / limited | IL_LINE2_ALLOWANCES_UNSUPPORTED | 2026 | Add Line 2 allowance input when approved. |
| Indiana (IN) | Limited | partial_support / limited | IN_COUNTY_TAX_UNSUPPORTED; IN_WH4_CUSTOMIZATION_UNSUPPORTED | 2026 | Add county withholding and WH-4 input model only when source-backed. |
| Iowa (IA) | Limited | partial_support / limited | IA_LEGACY_W4_UNSUPPORTED | 2026 | Future legacy form support phase. |
| Kansas (KS) | Limited | partial_support / limited | KS_K4_DEPENDENT_CUSTOMIZATION_UNSUPPORTED | 2026 | Add K-4 dependent customization only when source-backed. |
| Kentucky (KY) | Supported | official_2026 / supported | None | 2026 | Keep source evidence current. |
| Louisiana (LA) | Supported | official_2026 / supported | None | 2026 | Keep tests current. |
| Maine (ME) | Limited | partial_support / limited | ME_PHASEOUT_MODEL_NEEDED | 2026 | Add standard deduction phase-out when source-backed. |
| Maryland (MD) | Limited | partial_support / limited | MD_COUNTY_LOCAL_TAX_UNSUPPORTED | 2026 | Add county/local tax model when county input is available. |
| Massachusetts (MA) | Limited | partial_support / limited | MA_YTD_DEDUCTION_CAP_ASSUMPTION; MA_SUPPLEMENTAL_WAGE_METHOD_UNSUPPORTED | 2026 | Add year-to-date payroll state only if exact pre-cap paycheck estimation is required. |
| Michigan (MI) | Supported | official_2026 / supported | None | 2026 | Keep tests current. |
| Minnesota (MN) | Limited | partial_support / limited | MN_SPECIAL_CERTIFICATE_PATHS_UNSUPPORTED | 2026 | Add special paths only when source-backed. |
| Mississippi (MS) | Limited | partial_support / limited | MS_MARRIED_BOTH_WORK_CUSTOM_EXEMPTION_SPLIT_DEFERRED | 2026 | Add custom married-both-work exemption split model if approved. |
| Missouri (MO) | Limited | partial_support / limited | MO_MARRIED_STATUS_SCOPE_LIMITED | 2026 | Add Missouri-specific married spouse-work status input if needed. |
| Montana (MT) | Supported | official_2026 / supported | None | 2026 | Keep tests current. |
| Nebraska (NE) | Limited | partial_support / limited | NE_EMPLOYER_SIZE_MINIMUM_UNSUPPORTED | 2026 | Add employer-size minimum procedure only with explicit employer-size input. |
| Nevada (NV) | No income tax | official_2026 / supported | None | 2026 | Keep source evidence current. |
| New Hampshire (NH) | No income tax | official_2026 / supported | None | 2026 | Keep source evidence current. |
| New Jersey (NJ) | Limited | partial_support / limited | NJ_WAGE_CHART_METHOD_UNSUPPORTED; NJ_STATUS_E_UNSUPPORTED; NJ_PROPERTY_TAX_DEDUCTION_UNSUPPORTED; NJ_PRETAX_WAGE_SCOPE_LIMITED | 2026 | Add status E and broader state-wage inputs only with explicit input models. |
| New Mexico (NM) | Limited | partial_support / limited | NM_SUPPLEMENTAL_WAGE_METHOD_UNSUPPORTED | 2026 | Add supplemental wage method only when source-backed. |
| New York (NY) | Limited | prior_year_used / limited | PRIOR_YEAR_STATE_TABLE | 2026 | Build NY withholding-method strategy. |
| North Carolina (NC) | Limited | partial_support / limited | NC_DEFAULT_NO_ALLOWANCE_ONLY | 2026 | Add certificate variants only when source-backed. |
| North Dakota (ND) | Limited | partial_support / limited | ND_PRE2020_W4_UNSUPPORTED | 2026 | Add legacy/pre-2020 method only with explicit input model. |
| Ohio (OH) | Supported | official_2026 / supported | None | 2026 | Keep tests current. |
| Oklahoma (OK) | Limited | partial_support / limited | OK_HOH_UNSUPPORTED | 2026 | Decide whether head-of-household can be source-mapped; wage-bracket table lookup remains deferred. |
| Oregon (OR) | Limited | partial_support / limited | OR_STATEWIDE_TRANSIT_TAX_UNSUPPORTED | 2026 | Add transit tax and allowance-mismatch path when source-backed. |
| Pennsylvania (PA) | Supported | official_2026 / supported | None | 2026 | Keep tests current. |
| Rhode Island (RI) | Supported | official_2026 / supported | None | 2026 | Keep official booklet and NFC cross-check evidence current. |
| South Carolina (SC) | Supported | official_2026 / supported | None | 2026 | Keep tests current. |
| South Dakota (SD) | No income tax | official_2026 / supported | None | 2026 | Keep source evidence current. |
| Tennessee (TN) | No income tax | official_2026 / supported | None | 2026 | Keep source evidence current. |
| Texas (TX) | No income tax | official_2026 / supported | None | 2026 | Keep source evidence current. |
| Utah (UT) | Limited | partial_support / limited | UT_SPECIAL_PATHS_UNSUPPORTED | 2026 | Add special exclusions and additional pay frequencies only when needed. |
| Vermont (VT) | Limited | partial_support / limited | VT_SUPPLEMENTAL_WITHHOLDING_ADD_ON_UNSUPPORTED | 2026 | Add supplemental withholding add-on only when source-backed. |
| Virginia (VA) | Limited | partial_support / limited | VA_VA4_CUSTOM_SCOPE_LIMITED | 2026 | Add VA-4 age/blind/additional exemption inputs only when source-backed. |
| Washington (WA) | No income tax | official_2026 / supported | None | 2026 | Keep source evidence current. |
| West Virginia (WV) | Limited | partial_support / limited | WV_TWO_EARNER_SELECTION_REQUIRED | 2026 | Keep the explicit two-earner worksheet selection visible in calculator guidance. |
| Wisconsin (WI) | Limited | partial_support / limited | WI_WT4_CUSTOM_SCOPE_LIMITED | 2026 | Add custom WT-4 exemption election inputs only when source-backed. |
| Wyoming (WY) | No income tax | official_2026 / supported | None | 2026 | Keep source evidence current. |
| District of Columbia (DC) | Limited | partial_support / limited | DC_RESIDENT_INCOME_TAX_ESTIMATE_ONLY | 2026 | Verify and model official employer-withholding method after DC publishes reviewed D-4 guidance. |