One approach to a complete TSP Withdrawal is to make an election to make a complete withdrawal by making monthly withdrawals over a significant time period. For tax purposes you would want to elect a monthly amount which keeps your rate of taxation at the lowest possible rate. i.e. if you can receive 10,000 and keep your tax rate under 15% great and wonderful. Pulling all of your funds out in a lump sum is probably the most expensive way for tax purposes. Another consideration is the RMD requirement to calculate and take out funds once you reach 70 1/2. Consider whether to wait until 70 1/2 to start withdrawing funds (larger taxable amount with a potential higher tax rate and cost) or to start withdrawing funds earlier than 70 1/2 which should lower your tax cost assuming you believe tax rates are likely to increase in the future. This is certainly a personal decision and not to say I have all the answers but my call was to start at age 62 (retirement year) withdrawing my TSP account 4% a year over a significant time period. So far I have managed to keep my tax rate on my TSP account withdrawals under 15%. You can change the withdrawal amount annually. JMHO Good luck fellow TSP'rs!