It is on the books to allow a retired person to fly as a TR in both the ANG and the Reserve, but no one is doing it right now. The 340th FTG is not looking at retired AD guys right now and we were the last in AFRC to hire from that pool.

If you go to the ARC as an AGR then you are not retired, you are still on AD, so yes in theory you could get hired as a person with 20 years AD time into one of these positions, but not likely. You would be hurting the other guys in the unit who are trying to get promoted and move up by taking an O-4 or higher slot

You could not retire, then join as a TR, but you would need to work about 10 days a month of active duty or 8 days or so of inactive duty double pay days to get the same money in your pocket as your retirement check would have been. There are some advantages to this, but they are extremely rare. For example, an O-4 in an AGR billet has been selected for O-5, but can't pin on the new rank due to no available AGR spots or an unwillingness to move units or jobs to get the new rank. That O-4 then gets to 20 years of total active duty and could retire and earn an O-4 retirement check. That O-4 elects to revert to TR after getting 20 active years, since TR spots are allowed to overgrade (ie you can be an O-5 in an O-4 spot on the manning doc) they could pin on their new rank. If they got three good years time in grade as an O-5, they could retire as an O-5. But their retirement check would be an active duty O-4's check until age 60 when it would re-gonkulate and convert to an O-5 retirement. If they earned 1095 points of active duty time (3 x 365 days) while serving as a TR, which is hard to do without a lot of deployments and activations, they could retire as an O-5 instantly. There are some other considerations, but that is the simplest way I can think of to explain it.

If someone chose such a course of action, they would then have none of their retirement benefits from their AD/AGR job until they actually retired. So you would not have the healthcare you had on AD/AGR status unless you were on some sort of 31 day order or longer.

As others have said, you have to be a TR in the unit as a condition of ART/Technician employment. So to be an ART after earning an AD retirement, you would once again have to pretty much not retire in order to be hired as a TR, then be hired for an ART/Guard Technician job. A person in that situation would be financially better off to retire and get a GS job as a UPT sim instructor or something else not directly tied to a military reserve position. Then they would be truly double dipping. The GS salary plus the check of the month for brushing your teeth in the morning from all those years of AD service.

Hope that answers your questions.