I am a federal employee age 50, next month, and will be retiring with 24 years service, special category. Part of my retirement consists of the TSP. I am seeking to withdraw on a monthly basis, but do not want to incur the IRS 10% penaly. The TSP offers monthly withdrawals calculated on life expectancy or a 'series of periodic' withdrawals if they will last over 10 years (TSP.gov Calculators). With the later, you can indicate an arbitrary monthly withdrawal amount, as long as it will last 10 years. TSP does not indicate if this method qualifies for the 72t exception. They referred me to the IRS.Can I do a 72t calculation of my own, say using the Amortization method, plug that monthly figure in as a monthly withdrawal (TSP Form 70) and claim it as a SEPP withdrawal on the IRS form 5329? The other question is that the TSP takes a while to process requests. So if I submit the TSP form 70 in early February, I may not start receiving monthly withdrawals until March or April. Would this be OK under the 72t as I would not be taking a full annual withdrawal in 2009. In 2010 I would based on an entire 12 month withdrawal. Also, if I submit my TSP 70 in February, what month Mid-Term Interest 120% calculation could I use ?In the end, would it just be better to roll over the TSP into an IRA, say with Vanguard, and start a SEPP with them?Thanks.Dave