am I getting my highest social security monthly payments including my 3 years of military service and being stationed in korea.

Hi,

If all of your active duty was after 1967, or if you answered yes to the question on your Social Security application asking if you had any active military service prior to 1968 then you are almost certainly getting the proper credits for your service (https://www.ssa.gov/OP_Home/handbook/handbook.09/handbook-0953.html). There is no way to tell for sure without checking your Social Security records, though, so if you are in doubt you would need to contact them for confirmation.

Best, Jerry