What happens if the exchange cannot be completed within 180 days? Should I consider a 1031 reverse exchange?

If the 1031 exchange period exceeds 180 days, then the exchange is outside the safe harbor of Rev. Proc. 2000-37. With careful planning, it is possible to structure a 1031 reverse exchange (See Case Studies 2 & 5) that will go beyond 180 days, but the taxpayer will lose the presumptions that accompany compliance with the safe harbor.