If you receive a gift of property and your basis in it is figured using the donor's basis, your holding period includes the donor's holding period.

I was given a part of my mother's real property in 2012.  In 2018 and 2019 I had to invest in the property, by putting on a new roof, remodel the inside with new kitchen cabinets, new flooring, new plumbing fixtures, and a retaining wall, new carport and various other items.  We have a contract pending for Feb. of 2020,  My mother passed away in Apr. 2019, and I will be selling this property.   I have serval questions; What is my basis? Can I adjust my basis by all of the improvements that have been made in the last few years? Does the dates of the improvements matter? And, how do I figure my basis? thank you for this service. Deb

@Deborah Caines I am sorry for your loss. 

You need to know your mother's basis in the property because you will use that figure (as a carryover basis) for the share that she gifted to you. 

You also need to know the fair market value of the property on the date of death (April 2019) of your mother since her share will be stepped up to its fair market value. 

Any improvements you made to the property will be added to the basis for the property, but the cost of improvements made prior to the death of your mother will be split between your share and her share (the latter of which will receive a stepped up basis regardless).