Guaranteed Healthcare

I am 64 years old and was hoping to retire from a university in two more years. However, a year ago I had surgery to remove a stage 1 kidney cancer tumor. At the time I was so thankful it was found early, but this year I am realizing that I'll likely be uninsurable after retiring - or else the premiums would be so high that I'd have nothing to live on. Perhaps it's fortunate that I am learning this hard fact now, and that my health is good enough that I can continue working - because it appears I'll be working for many more years in order to have health insurance.