When can i withdraw from my TSP without an early withdrawal penalty tax equal to 10%?

If you receive a TSP withdrawal payment before you reach age 59½, in addition to the regular income tax, you may have to pay an early withdrawal penalty tax equal to 10% of any taxable portion of the payment that is not transferred or rolled over. However, if you separate from service during or after the year you reach age 55 (or the year you reach age 50 if you are a public safety employee as defined by section 72(t)(10)(B)(ii) of the Internal Revenue Code), then the 10% early withdrawal penalty tax does not apply. There are other circumstances in which the 10% early withdrawal penalty does not apply that are not associated with your age at retirement. For more information, read the TSP tax notice "Important Tax Information About Payments from Your TSP Account."

Resource: www.tsp.gov