Per IRS Publication 3, Armed Forces' Tax Guide, on page 11:

Are My Travel Expenses as a Reservist Deductible?

If you are a member of a reserve component of the Armed Forces and you travel more than 100 miles away from home in connection with your performance of services as a member of the reserves, you can deduct your unreimbursed travel expenses on your tax return. Include all unreimbursed expenses from the time you leave home until the time you return home. See How To Report My Reserve-Related Travel Expenses below for information on how to report these expenses on your tax return.

Am I a Member of a Reserve Component?

You are a member of a reserve component of the Armed Forces if you are in:

• The Army, Navy, Marine Corps, Air Force, or Coast Guard Reserve;
• The Army National Guard of the United States;
• The Air National Guard of the United States; or
• The Ready Reserve Corps of the Public Health Service.

To enter the deduction on Schedule 1 (Form 1040) Additional Income and Adjustments to Income, Line 11:

1. From within your TaxAct return (Online or Desktop), click Federal. On smaller devices, click in the upper left-hand corner, then click Federal.
2. Click Other Adjustments in the Federal Quick Q&A Topics menu to expand, then click National Guard/Reserve member from Form 2106.
3. Click + Add Form 2106 to create a new copy of the form or click Edit to review a form already created.
4. Continue with the interview process to enter all of the appropriate information.
5. On the screen titled Employee Expenses - Form 2106, enter the Occupation, then click Continue.
6. On the screen titled Employee Expenses - Occupation Related, check Armed Forces reservist, then click Continue.

Note. The business standard mileage rate for 2020 is 57.5 cents per mile.

Note that any link in the information above is updated each year automatically and will take you to the most recent version of the document at the time it is accessed.