Navigating the pitfalls and penalties of an early retirement can be difficult, but with a little guidance this can be a pain-free journey.

List of IRS exemptions to 10% early withdrawal penalty:
https://www.irs.gov/Retirement-Plans/Plan-Participant,-Employee/Retirement-Topics—Tax-on-Early-Distributions

Helpful article outlining specifics of pre-59.5 withdrawals:
http://www.fedsmith.com/2015/04/05/can-you-retire-before-age-59-5-without-incurring-tsp-penalties/