The U.S. Army could have 483,000 troops by the end of 2018 but that will be difficult. Not only is the Army trying to increase its personnel strength it is having a hard time keeping those already in uniform. Historically low unemployment rates have made it difficult to hang onto current personnel and attract new recruits. So the Army will, at the end of 2018, fall short of its authorized strength by about 6,000. Meanwhile, the Army personnel problems will increase because the 2012 plan to reduce Army personnel strength to 450,000 was reversed in 2017 and now the Army has to get back to at least 500,000 personnel, or at least try.
I know a guy who retired from active duty (motor pool, I think) a few years ago, who re-upped into the Guard in some technical MOS, signals or something. However, most of the guys and gals who left the Army that I know, aren't going to re-up. Some are already contractors downrange, some looking into it.