Q. What is the percentage of return if I invest the balance of my Thrift Savings Plan account in the annuity provided by TSP?
A. The monthly payment depends upon your circumstances and the interest rate environment when you purchase the annuity. You can run a quote at www.tsp.gov. The return on investment from a TSP annuity can’t be known in advance, however. You’ll have to wait until the payments stop to figure it out. To illustrate, what if you buy a single life annuity with no refund and then die right away? Your return on investment will be hugely negative. The longer you live, the better the rate of return.