Got hit with a large medical bill from 2022

Im in California if that matters. I was hospitalized back in April 2022 for a few days. After I got out, I received numerous bills from the hospital and Drs that treathed me. It seemed like a new bill came in once a week for a few months. I was able to pay the bills and thought I was done with it until today. Today I received another hospital/Dr bill dated back to April 2022. Looked it up and it seems, the insurance I had back then paid some of the bill and they are charging me for the remainder. Its took me almost 6 months to pay down the original bills and Im barely able to catch up on my finances now. Can they still charge me now for something almost 3 years ago?