# Iowa — State conformity to federal Section 179 and bonus depreciation rules For Iowa, section 179 conformity is conforms; state section 179 cap is federal limit applies (fully conforms beginning tax year 2020); state section 179 phase-out is federal phase-out applies; bonus depreciation conformity is decouples — requires add-back; add-back rule is Iowa does not conform to bonus depreciation; adjustment required, recorded from its source on 2026-08-15. - **State:** Iowa _(verified: appears in the quote below)_ - **Section 179 conformity:** conforms - **State Section 179 cap:** federal limit applies (fully conforms beginning tax year 2020) _(verified: appears in the quote below)_ - **State Section 179 phase-out:** federal phase-out applies - **Bonus depreciation conformity:** decouples — requires add-back - **Add-back rule:** Iowa does not conform to bonus depreciation; adjustment required - **Has income tax:** yes _(verified: appears in the quote below)_ - **Statute or guidance citation:** IRC § 179 _(verified: appears in the quote below)_ ## What the source says > State Follows Bonus Depreciation-TCJA of 2017 : No Iowa does not conform to the Tax Cuts and Jobs Act provision that provides a 100% first-year deduction for the adjusted basis is allowed for qualified property acquired and placed in service after September 27, 2017, and before January 1, 2023. State Follows IRC § 179-TCJA of 2017 : Yes The increased expensing allowance under IRC § 179 , as amended by the Tax Cut and Jobs Act applies in computing net income for Iowa state tax purposes for tax years beginning on or after January 1, 2018, subject to the limitations for tax years prior to January 1, 2020. The Iowa Section 179 deduction limitation for tax year 2019 is $100,000 (less than the $1,020,000 federal limit) with a $400,000 phaseout for all taxpayers. Iowa will fully conform to the IRC § 179 deduction amounts beginning in tax year 2020. ## Sources disagree More than one authority states this, and they do not state the same thing. Both are reproduced with the source each came from. ### State Section 179 cap accountants.intuit.com says state section 179 cap is **federal limit applies (fully conforms beginning tax year 2020)**, as of 2026-08-15. > State Follows Bonus Depreciation-TCJA of 2017 : No Iowa does not conform to the Tax Cuts and Jobs Act provision that provides a 100% first-year deduction for the adjusted basis is allowed for qualified property acquired and placed in service after September 27, 2017, and before January 1, 2023. State Follows IRC § 179-TCJA of 2017 : Yes The increased expensing allowance under IRC § 179 , as amended by the Tax Cut and Jobs Act applies in computing net income for Iowa state tax purposes for tax years beginning on or after January 1, 2018, subject to the limitations for tax years prior to January 1, 2020. The Iowa Section 179 deduction limitation for tax year 2019 is $100,000 (less than the $1,020,000 federal limit) with a $400,000 phaseout for all taxpayers. Iowa will fully conform to the IRC § 179 deduction amounts beginning in tax year 2020. Source: https://accountants.intuit.com/support/en-us/help-article/asset-depreciation/state-conformity-special-depreciation-allowance/L27kRyetJ_US_en_US crosslinktax.com says state section 179 cap is **federal limit applies**, as of 2026-08-15. > Iowa | Yes | Yes | Source: https://www.crosslinktax.com/customer-resources/tax-resource-center/tax-updates/state-compliance-with-federal-bonus-depreciation-and-section-179-expensing-2025/ ### Bonus depreciation conformity accountants.intuit.com says bonus depreciation conformity is **decouples — requires add-back**, as of 2026-08-15. > State Follows Bonus Depreciation-TCJA of 2017 : No Iowa does not conform to the Tax Cuts and Jobs Act provision that provides a 100% first-year deduction for the adjusted basis is allowed for qualified property acquired and placed in service after September 27, 2017, and before January 1, 2023. State Follows IRC § 179-TCJA of 2017 : Yes The increased expensing allowance under IRC § 179 , as amended by the Tax Cut and Jobs Act applies in computing net income for Iowa state tax purposes for tax years beginning on or after January 1, 2018, subject to the limitations for tax years prior to January 1, 2020. The Iowa Section 179 deduction limitation for tax year 2019 is $100,000 (less than the $1,020,000 federal limit) with a $400,000 phaseout for all taxpayers. Iowa will fully conform to the IRC § 179 deduction amounts beginning in tax year 2020. Source: https://accountants.intuit.com/support/en-us/help-article/asset-depreciation/state-conformity-special-depreciation-allowance/L27kRyetJ_US_en_US crosslinktax.com says bonus depreciation conformity is **conforms**, as of 2026-08-15. > Iowa | Yes | Yes | Source: https://www.crosslinktax.com/customer-resources/tax-resource-center/tax-updates/state-compliance-with-federal-bonus-depreciation-and-section-179-expensing-2025/ ### Add-back rule accountants.intuit.com says add-back rule is **Iowa does not conform to bonus depreciation; adjustment required**, as of 2026-08-15. > State Follows Bonus Depreciation-TCJA of 2017 : No Iowa does not conform to the Tax Cuts and Jobs Act provision that provides a 100% first-year deduction for the adjusted basis is allowed for qualified property acquired and placed in service after September 27, 2017, and before January 1, 2023. State Follows IRC § 179-TCJA of 2017 : Yes The increased expensing allowance under IRC § 179 , as amended by the Tax Cut and Jobs Act applies in computing net income for Iowa state tax purposes for tax years beginning on or after January 1, 2018, subject to the limitations for tax years prior to January 1, 2020. The Iowa Section 179 deduction limitation for tax year 2019 is $100,000 (less than the $1,020,000 federal limit) with a $400,000 phaseout for all taxpayers. Iowa will fully conform to the IRC § 179 deduction amounts beginning in tax year 2020. Source: https://accountants.intuit.com/support/en-us/help-article/asset-depreciation/state-conformity-special-depreciation-allowance/L27kRyetJ_US_en_US crosslinktax.com says add-back rule is **N/A**, as of 2026-08-15. > Iowa | Yes | Yes | Source: https://www.crosslinktax.com/customer-resources/tax-resource-center/tax-updates/state-compliance-with-federal-bonus-depreciation-and-section-179-expensing-2025/ ## Source - https://accountants.intuit.com/support/en-us/help-article/asset-depreciation/state-conformity-special-depreciation-allowance/L27kRyetJ_US_en_US - https://www.crosslinktax.com/customer-resources/tax-resource-center/tax-updates/state-compliance-with-federal-bonus-depreciation-and-section-179-expensing-2025/ Last verified: 2026-08-15. Review by: 2027-08-15. Part of [State conformity to federal Section 179 and bonus depreciation rules](https://referencesource.org/state-section-179-bonus-depreciation-conformity/).