Does CPS Have to Stop Services?

I'm wanting to find out if anyone can tell me what experiences they have had at the 18 month hearing. Does the court have to terminate services at this point if the case isn't moving towards reunification? Our case is so confusing to everyone that nobody can seem to tell us what to expect. SO, I guess I'm just looking for input from others who are more experienced than I to see if there is a pattern here. Also, I thought this would be best included in the California threads since that is where the case is. Any input is greatly appreciated.