Assuming the per diem was a reimbursement for work related travel, including meals. you may have a deduction for travel expenses that can be used to offset the income through itemized deductions. Use Deductions & Credits for all itemized deductions.
In TurboTax for job related expenses specifically do the following:
- In the search box type employee business expenses
- Jump to employee business expenses
- If you are a transportation worker be sure to check that box for special allowances
- follow the prompts DO NOT enter any reimbursements that were included in box 1 of your W2.*
* I have included a screenshot showing you this section.
