Originally Posted by
cruiseclimb
Most branches want you to have completed OCS by the time you are 27 yrs old.
Last I checked (USAF / Navy, anyway) you
have to start UPT prior to your 27th birthday. No waivers or exceptions. Guard and Reserves, too. Just completing OCS won't cut it if there's any delay prior to your flight training.
With USMC aviation you could start a little older, but after comissioning you have to serve in a rifle company for a year or more before you'll start flight training. Every Marine is a rifleman first.
My info may be a little old, but bottom line- don't wait until you're 24 or 25 to start the ball rolling.