Idaho recently enacted legislation updating how the state conforms to federal tax law under the new tax bill. These changes are retroactive to January 1, 2025, and may affect your Idaho income tax return.

Because Idaho adopted most of the federal changes made by the new tax bill:

• Certain new federal deductions may now also apply to your Idaho return. Examples may include changes related to tip income, overtime pay, or certain senior deductions.
• Idaho taxable income calculations may change for some taxpayers.
• Some business depreciation rules may still differ from federal treatment.

Important – Filing Guidance

The Idaho State Tax Commission announced on March 3, 2026, that Form 40 and Form 43 have been updated to reflect the larger standard deduction amounts under the new conformity changes. These changes will be implemented in TaxAct soon.

Already Filed Your Idaho Return?

• Taxpayers who already filed using the previous standard deduction amounts will automatically receive the larger standard deduction; no amended return is required.
• Taxpayers who itemized and filed without including the applicable Schedule 1-A deductions on their Idaho return will need to file an amended return to reflect the corrected amount.

We will provide more information soon.

For updates directly from the state, visit the Idaho State Tax Commission website.

Note  This new tax bill, was signed into law on July 4, 2025. The One Big Beautiful Bill Act (OBBB or OB3) is now also being referred to by lawmakers as the Working Families Tax Cut Act. You may see one or both names used, but they refer to the same set of tax changes.