What is the Annuity Interest Rate?

Although the TSP annuity interest rate changes monthly, for purposes of the Federal Ballpark E$timate, we use 2.250% as the default rate (a mean of past year data). You can choose a different value. Refer to the following link on the TSP website for the Historical Annuity Rate Index at: https://www.tsp.gov/whatsnew/rates/annuityRateIndex.shtml . For purposes of the Federal Ballpark E$timate, we use the default rate or the rate you select in the calculation for both the TSP and Non-TSP.