The rules may have changed since I retired, but at least back then the advice was to start Social Security at 62, which I did. Six or seven years later I discovered I could have gotten considerably more if I had waited until 70 to start. I also discovered I could pay back what I had already received and restart at the higher rate, so I waited until just before 70, scraped together the cash, paid it to Social Security, and restarted at the higher rate. May seem foolish, but I did the math and that Social Security rate increase amounted to 10% interest on the pay back cash. Not suggesting anyone else do as I did — just a story of my experience.