# Montana — State conformity to federal Section 179 and bonus depreciation rules

For Montana, section 179 conformity is conforms; state section 179 cap is federal limit applies; state section 179 phase-out is federal phase-out applies; bonus depreciation conformity is conforms; add-back rule is N/A, recorded from its source on 2026-08-15.

- **State:** Montana _(verified: appears in the quote below)_
- **Section 179 conformity:** conforms _(verified: appears in the quote below)_
- **State Section 179 cap:** federal limit applies
- **State Section 179 phase-out:** federal phase-out applies
- **Bonus depreciation conformity:** conforms _(verified: appears in the quote below)_
- **Add-back rule:** N/A
- **IRC conformity date:** rolling conformity
- **Has income tax:** yes _(verified: appears in the quote below)_

## What the source says

> State Follows Bonus Depreciation-TCJA of 2017 : Yes Montana follows federal law. State Follows IRC § 179-TCJA of 2017 : Yes Montana follows federal law and so conforms to the conforms to the provisions of the Tax Cuts and Jobs Act that increase the maximum amount a taxpayer may expense under IRC Sec. 179 to $1 million, increases the phase-out threshold amount to $2.5 million, and provides for indexing for inflation.

## What crosslinktax.com says

> Montana | 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/).