DanKarnage28 -- Time towards retirement only begins the day you become a regular carrier.
-- "Cliff" pretty much summed up your RCA time.
-- Creditable service time may be from some other branch of the government, such as if you were in the military, you might be able to buy back that service time -- provided you did not retire from the military and are drawing a retirement check from them. You could waive that military retirement check, but living on RCA wages probably won't be possible. Someone at Shared Services ( 1-877-477-3273 ) should be able to answer your questions.
-- No, you don't have to work for 30 years as a regular to retire. Your eligibility to retire will depend on your age, your years of service as a regular, and what type of retirement you choose.
-- Check the July 2016 issue of the national magazine for an article entitled "Am I Ready to Retire?" If you didn't keep it or no one in the office did, a union member can access it via the NRLCA web site - magazine section / archives.
-- You can also visit the opm.gov web site for tips on retirement and its many options.