Connecticut
For Connecticut, section 179 conformity is conforms with state cap; state section 179 cap is 80% of IRC § 179 deduction is disallowed; 25% of disallowed portion allowed in each of the four succeeding income years; state section 179 phase-out is state rules apply; bonus depreciation conformity is decouples — requires add-back; add-back rule is any additional allowance for bonus depreciation under IRC § 168(k) must be added back; 25% of the disallowed deduction may be deducted for each of the four succeeding tax years, recorded from its source on 2026-08-15.
- State
- Connecticut verified
- Section 179 conformity
- conforms with state cap
- State Section 179 cap
- 80% of IRC § 179 deduction is disallowed; 25% of disallowed portion allowed in each of the four succeeding income years
- State Section 179 phase-out
- state rules apply
- Bonus depreciation conformity
- decouples — requires add-back
- Add-back rule
- any additional allowance for bonus depreciation under IRC § 168(k) must be added back; 25% of the disallowed deduction may be deducted for each of the four succeeding tax years
- Has income tax
- yes verified
What the source says
Yes Colorado conforms to the Tax Cuts and Jobs Act provision that increases the maximum amount a taxpayer may expense under IRC Section 179 to $1 million, increases the phase-out threshold amount to $2.5 million, and provides for indexing for inflation State Follows Bonus Depreciation-TCJA of 2017 : No Connecticut
— accountants.intuit.com, retrieved 2026-08-15
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 — deciding between them is yours, not ours.
State Section 179 cap
accountants.intuit.com says state section 179 cap is 80% of IRC § 179 deduction is disallowed; 25% of disallowed portion allowed in each of the four succeeding income years, as of 2026-08-15.
Yes Colorado conforms to the Tax Cuts and Jobs Act provision that increases the maximum amount a taxpayer may expense under IRC Section 179 to $1 million, increases the phase-out threshold amount to $2.5 million, and provides for indexing for inflation State Follows Bonus Depreciation-TCJA of 2017 : No Connecticut
crosslinktax.com says state section 179 cap is spread over 4 years, as of 2026-08-15.
Connecticut | Over 4 years | Over 4 years |
Add-back rule
accountants.intuit.com says add-back rule is any additional allowance for bonus depreciation under IRC § 168(k) must be added back; 25% of the disallowed deduction may be deducted for each of the four succeeding tax years, as of 2026-08-15.
Yes Colorado conforms to the Tax Cuts and Jobs Act provision that increases the maximum amount a taxpayer may expense under IRC Section 179 to $1 million, increases the phase-out threshold amount to $2.5 million, and provides for indexing for inflation State Follows Bonus Depreciation-TCJA of 2017 : No Connecticut
crosslinktax.com says add-back rule is bonus depreciation spread over 4 years, as of 2026-08-15.
Connecticut | Over 4 years | Over 4 years |
Sources
- accountants.intuit.comhttps://accountants.intuit.com/support/en-us/help-article/asset-depreciation/state-conformity-special-depreciation-allowance/L27kRyetJ_US_en_US
- crosslinktax.comhttps://www.crosslinktax.com/customer-resources/tax-resource-center/tax-updates/state-compliance-with-federal-bonus-depreciation-and-section-179-expensing-2025/