I saw my first IC for about 8-10 months, until we both felt that she had done everything she could for me. Then I took a break from IC and after 6-12 months of a break I started to see a new IC. My second IC covered different things than my first IC and I was in a different place and had different issues than when I was seeing my first IC. I saw my second IC for 18-24 months. Once again we both felt she had done everything she could for me.
I would have returned to my second IC at certain points since then when I was feeling low or a little lost, but she moved out of state.
IMO, if you feel that you have reached the limit where your IC can help then it is time to take a break and/or find someone else who may use a different approach. I did have to tell my story again to the second IC, but that only took one session.