I've been retired for 3 years, what are my prospects for re-entering the reserves and getting back in where I was?

I don't know about CSM , however a friend and Soldier of mine retired as a 1SG. I told him then that he wasn't ready as he was still fit, doing an awesome job and enjoyed the service. He was out two years and came back in, the Army brought him back at MSG and he worked with dignified transfers. That was back 2010 time frame. I would contact your Regimental CSM and see if you could get them on board they would know where and if there was a need for SGM in your branch. The problem with bringing us old dogs back is that it stymies a young buck from progressing.

Have you looked into a retiree recall?

CSM, did you take a Reserve or Active Duty retirement? If reserve, reach out to SLDO at HRC to discuss retired reserve to IRR options, then work with a 79V retention NCO to transfer to a TPU. Message me if you want a POC.