Iowa’s 3.8% rate and its narrow gain deduction
Iowa moved to a single 3.8% rate in 2025, so most gains cost 3.8% of the added Iowa taxable income; a $50,000 increase adds $1,900 before credits. Iowa also stopped taxing retirement income for people 55 and older, but that exclusion covers pensions and IRA distributions, not a sale in a taxable account.
Iowa’s capital gain deduction is limited to the specific transactions described on the IA 100 schedules, mostly farm and business property that was both held and actively worked for long periods. Ordinary stocks, bonds and fund shares do not qualify, however long they were held. The calculator asks for Iowa taxable income after any deduction you have documented.
Iowa’s flat rate follows the state taxable-income calculation
Iowa Code §422.5 sets the individual income-tax rate at 3.8% for the current statutory period. The percentage applies to Iowa taxable income. It does not establish that every federally reported capital gain belongs unchanged in the Iowa tax base, or that every sale qualifies for a capital-gains deduction.
The department’s expanded instructions and IA 100 forms address particular qualifying transactions. A deduction for eligible property or a business transaction should be documented under its own requirements. Holding brokerage shares for a long period does not automatically satisfy a transaction-specific Iowa deduction.
Prepare Iowa taxable income in both scenarios, incorporating approved adjustments, deductions and the relevant allocation. The base-comparison mode uses the confirmed 3.8% rate before credits; an independently prepared $20,000 base increase therefore adds $760 before credits. Use final state liabilities where credits or nonresident allocation change the result. The federal worksheet keeps its own long-term gain and exclusion inputs separate from an Iowa-only deduction.
Iowa preparation checklist
- Iowa taxable-income reconciliation
- Applicable IA 100 transaction requirements
- Nonresident allocation and final credits