Not sure if it has been discussed on this forum or not, but the Law Enforcement Officers Safety Act (LEOSA) now applies to active and retired military police. The Air Force has been up and running theirs for awhile. The Army just got theirs going recently and the Navy which should include the USMC, are still evolving. The National Defense Authorization Act for 2013 amended LEOSA to make these categories eligible to apply and receive a concealed carry authorization which is accepted in all 50 states. Just Google LEOSA and you can see the requirements and start the process from there. The cost varies depending on where you do the security clearance and some other stuff but it's around $200 for lifetime permit. I was hesitant at first because of the "weapons qualification" requirements, but it is easier to maintain than I thought.