I purchased land in 2004 for 75k then bought my ex out of it for 20k and put 30k in improvements on it. I sold it for 120k in 2017. Will I owe taxes?

[Opus 17]

The depends on what you mean by "I bought land in 2004".  If you alone owned the land, why did you buy out your ex?  Or did you buy it together?

[SweetieJean]

Was it ever rented out?

[theedbergcart]

Bought married. got divorced and bought her out. vacant land never rented

[SweetieJean]

Then what were the improvements?

[theedbergcart]

driveway, pad cut for foundation, well and septic system

[Opus 17]

Your cost basis is $105K.  The amount you paid to your ex as part of the division of property in the divorce settlement does not alter your cost basis.  If you sell for $120K, you will have a $15,000 capital gain on which you will owe 15% long term cap gains tax.  (Although you can deduct selling expenses like your attorney, any required inspections, transfer taxes, etc. and real estate commission, so your gain will probably be less.)