Question about 1031 and 121 exclusion

[Debbie C.]

I have a question for tax experts out there. Let’s say I did a 1031 exchange and chose a replacement property worth 100k, fully paid with cash from the exchange. Then I rent this property to my son and after two years time, added his name onto the property title. Once his name is added, can he sell it and claim the full 121 exemption for taxes (of up to 250k for single people), since he’s lived in the place for two years and it’s his primary residence? Or would this not be valid because me and my husband’s names are also on the title?

If this isn’t possible, is there any other way that I can let my son become an owner-occupant of this property so that he can claim 121 exemption when it’s sold?