Thanks to passage of the SECURE Act in January 2020, any TSP account holder turning 70.5 in 2020 can wait until they are age 72 to start taking Required Minimum Distributions (RMDs).  If you turned 70.5 prior to January 1, 2020 you are required to take a minimum distribution according to current rules in 2020.  See the bulletin board section (upper right) of the TSP website.