I have a tax client that purchased real estate 10 years ago for $50K (not principal residence) for the purpose of opening a group home but never did it.  He was approached by a government agency asking if he could sell it to them cause they needed the land for a project.  He sold it to them for $400K. He took $380K of the money and purchased another piece of property that will not be his principal residence.  Is there a way to report this transaction correctly so he doesn't pay taxes on the original gain of $350K since he re-invested the money?