One "mistake" I've made through my life was not to value liquidity and cash flow enough, especially in times of crisis. I've assumed I would always be able to work and thus was comfortable "locking up" most of my investments in "hard-to-tap places" in house equity, IRAs, 401(k)s, deferred comp, life insurance CV, etc. And for the house I had a 15 year loan, thinking I could have it close to paid off by the time I early retired. But then the unthinkable happened - bam, my job was eliminated and I was packaged out. Now I had enough from the buy out to pay the mortgage for almost 2 years, but at that moment I wish I had a 30 year mortgage so I could pay less. I took the opportunity anyway to sell my house and get a job in a much lower cost of living area. I would seriously be sure you're comfortable giving up the flexibility of having a 30-year and just making higher payments vs being locked into a 15 year. Also, you probably come out better ahead investing the difference anyway. But given what I went through, and how low mortgage rates are, I only see myself getting a 30 year for the next house I buy. And if I really want a paid off mortgage in retirement, I'll just take a lump sum distribution from a retirement account after age 59.5 and pay the mortgage off.