If the 1099-Misc shows the amount in box 3 - it is reportable as "other income" on line 21, page 1 of your 1040. The description may be "Reimbursed Expenses" or something similar. You will want to add a second entry with same payer and and the description "Actual Expenses" with a negative number to zero out the 1099-MISC.
Search "other taxable income" for input.
If you received income reported on a 1099-MISC, you may be treated as self-employed, but getting a 1099-MISC doesn't necessarily mean you'll be subject to self-employment tax.
It all depends on whether this is a recurring activity or a "one-off" activity that's infrequent, not related to your work, and wasn't performed in the tax year prior (or after) the tax year for which you received your 1099-MISC.
If you plan to continue the same type of work in the future, you will likely be considered self-employed, and therefore subject to the self-employment tax.
Generally speaking, self-employment income on form 1099-MISC is reported in Box 7, whereas "one-off" income belongs in Box 3.
