If you have plenty of money to put down 20% and still have a ton of reserve funds I think most should avoid PMI. If you can't put down 20% or it would greatly reduce reserve funds, depends on your credit score, honestly. If you have a great credit score (like 740+) it can be pretty minimal. I think mine equates to about $7,500 over 8-9 years. That is a pretty minimal cost considering I put down about $7k instead of $47k. Of course if your credit score is pretty rough PMI can start approaching $300. If it will take you years to get 20% to put down, one can argue housing appreciation and/or interest rates can cost you just as much though. Now one could put less down and invest the rest, potentially making more in the long run. However, that is getting pretty complicated and far from a sure thing. I think I would just take the sure thing where I pay no PMI and then spend less over the life of the loan in interest.