Your gain is calculated by contrasting the basis with the sales price. If you sold it for more than you purchased it, you have a gain. If you made any improvements, they are added to the purchase price. You must report any gain, regardless of whether or not you received a 1099-S or not.
Your mortgage has nothing to do with it. If you did have a gain, you might qualify for the exclusion.
Steps for reporting sale:
- Click on Federal Taxes (Personal using Home and Business)
- Click on Wages and Income (Personal Income using Home and Business)
- Click on I'll choose what I work on
- Scroll down to Less Common Income
- On Sale of Home (gain or loss), click the start or update button
