1031 Exchange Improvement Act This bill revises the tax rule allowing deferral of gain for like kind exchanges of commercial property. (That rule provides that no gain or loss shall be recognized on the exchange of real property held for productive use in a trade or business or for investment if such real property is exchanged solely for real property of like kind.) Specifically, the bill eliminates the requirement that a substitute property be identified within 45 days of the sale of the original property.