All states

Iowa

Flat rate

Notes

  • Iowa converted to a single FLAT rate of 3.80% for 2025 (Senate File 2442) — no brackets, same rate for every filing status and income level. The graduated brackets used through 2024 are gone. / 爱荷华州自 2025 年起改为 3.80% 的单一统一税率（参议院第 2442 号法案）——没有累进税档，所有报税身份和收入水平税率相同。截至 2024 年使用的累进税档已取消。
  • The deduction for FEDERAL INCOME TAX PAID is REPEALED. Iowa formerly let you deduct federal income tax; that deduction is fully phased out by 2025 and is not modelled. / 已废除「联邦所得税可抵扣」条款。爱荷华州过去允许抵扣已缴联邦所得税，该抵扣在 2025 年已完全取消，本模块不予建模。
  • The tax base is FEDERAL TAXABLE INCOME (Form 1040 line 15), not AGI. The redesigned IA 1040 now adopts the FEDERAL standard or itemized deduction (line 1d) — Iowa no longer has its own standard deduction. / 计税基数是联邦应税收入（1040 表第 15 行），而非 AGI。重新设计的 IA 1040 现采用联邦标准或分项扣除额（第 1d 行）——爱荷华州不再有自己的标准扣除额。
  • Unlike Colorado, Iowa requires NO state-income-tax addback for federal itemizers, so federal taxable income flows through directly. / 与科罗拉多州不同，爱荷华州对联邦分项扣除者不要求加回州所得税，因此联邦应税收入直接结转。
  • Low-income exemption: a filer owes $0 when Iowa taxable income (line 4) is at or below $9,000 (single / married filing separately) or $13,500 (married filing jointly / head of household). The higher age-65+ thresholds ($24,000 / $32,000) are NOT modelled (no age field). / 低收入豁免：当爱荷华州应税收入（第 4 行）不超过 9,000 美元（单身/分别申报）或 13,500 美元（联合申报/户主）时应税为 0。更高的 65 岁以上门槛（24,000/32,000 美元）未建模（无年龄字段）。
  • Not modelled: the optional alternate tax (4.3% on income over a $13,500/$32,000 exclusion, taken only when lower) and IA 1040 Schedule 1 modifications (retirement-income exclusions, U.S. government interest, 529 contributions, bonus-depreciation addbacks, etc.). / 未建模：可选的替代税（对超过 13,500/32,000 美元豁免额的部分按 4.3% 计税，仅在更低时采用）以及 IA 1040 附表 1 的调整项（退休收入豁免、美国政府利息、529 计划缴款、奖励性折旧加回等）。

Sources