I want to retire from federal law enforcement at age 50 with 26 years. I want to leave my money in TSP and begin drawing it at a later age, say 54 1/2? Can I leave my money in TSP, let TSP do my calculations based on life expectancy when I want to start withdrawing and have that meet the 72T withdrawl criteria? Also, it is my understanding that once you begin 72T withdrawls you can not change them for 5 years or is it until you reach age 59 1/2 or both? At age 60 would I then be able to switch to monthly payments of my choice?