I just made a few calls about DivorceCare around here and it seems you can jump in as long as there's a few sessions left. There's one that has 3 left nearby, starting tonight, so I hope to go there to check it out. Then they start again in September, so it seems this is common.
M 16 yrs, WH62, P54 3 adult blended kids EA 11/13, BD1 6/14 PA fall 14, BD2 2/15 Piecing 2015, BD3 12/15 Separated 4/16 WH moved OW in 5/16 Divorced 6/15/17