Q. Federal employee age 58, retiring with 30 years’ service and would like to take $109K from my non-Roth TSP to pay off mortgage. Besides Federal tax, would I also have to pay a 10 % penalty because I am not 59 1/2 years old? Would the federal withhold 20 % tor taxes or would it be more?A. There will be mandatory withholding of 20%, but the early withdrawal penalty will not be assessed. Details are available at https://www.tsp.gov/PDF/formspubs/tsp-536.pdf.