Please take a look at the hyperlink above. This is latest information that we have found. In short, the old rule from TSP that you have to retire the year you turn 50 or later to be able to touch your TSP money is out. As long as you work your 25 years and you are under the age of 50, you can now touch your TSP money without the 10% penalties.
U.S. Secret Service Uniformed Division Labor Committee