Our son is having to deal with coming off of my husband's insurance soon. He could stay on as a full-time student. However he went to community college and graduated (yea). My husband's employer extended the insurance for 3 months. They also sent us the COBRA form (which will be very expensive). However in NY there is an insurance called HealthyNY. It is for lower income or part-time work. As long as he qualifies, they will accept his pre-existing condition. The cost will still be high but about 1/2 of what COBRA would be. There is a choice of insurance companies. The one we are looking at is the most expensive but it is an offshoot of what we have now. The strangest thing I found is that he will have to go to his primary care for a referral (which we don't have to do on our insurance). That means to go to his future GI appointments (with the GI he is currently with) he will have to go to the primary doctor first just for a referral. Makes no sense to me but whatever.
Whatever you do, research now. Don't let your insurance lapse. I think there is a 63 day grace period. That will be the key to covering a pre-existing condition.