If you are a chaplain and your employer doesn’t exclude contributions made to your 403(b) account from your earned income, you may be able to take a deduction for those contributions on your tax return.
However, if your employer has agreed to exclude the contributions from your earned income, you won’t be allowed a deduction on your tax return.
If you can take a deduction, include your contributions on line 36 of the 2018 Schedule 1 (Form 1040). Enter the amount of your deduction and write "403(b)" on the dotted line next to line 36.
[EDITED 4-1-2019 1:25 PM PST]