Colorado Mileage Deduction 2026: Flat 4.4% State Tax

Colorado has a flat income tax of 4.4%. Your federal mileage deduction on Schedule C flows through to your Colorado return. Simple math: every $1,000 deducted saves $44 in state tax, on top of your federal savings.

The Savings

At 72.5¢/mile and 15,000 business miles:

Employer Reimbursement

Colorado does not require private employers to reimburse mileage for general business driving. The state does require reimbursement for uniform and tool expenses, but this does not extend to vehicle use.

How to Track Your Miles

Keep a mileage log with the date, destination, purpose, and miles for each trip. The IRS requires contemporaneous records, recorded as trips happen, not reconstructed later.

FAQ

Does Colorado's mileage deduction math work like other flat-tax states?

Yes. Colorado starts with federal taxable income and applies the 4.4% flat rate. Your Schedule C mileage deduction reduces federal AGI, which directly reduces your Colorado tax.

Are mountain driving miles deductible?

If the drive is for business purposes, yes. Miles between job sites, to client meetings, or to business locations all count. Your commute from home to your primary office does not.

Can W-2 employees deduct mileage in Colorado?

No. The mileage deduction for W-2 employees was permanently eliminated under the One Big Beautiful Bill. Colorado does not require employer reimbursement for mileage, so if your employer does not reimburse, you have no tax remedy.

Front Range or mountain town, every business mile counts. Start free →