I was working on a remodel of a dr's house. Fell 20 feet off a ladder the contractor on the job does not have workman's comp. Can I sue homeowners ins

I'm assuming this occurred in Pennsylvania.  You may be the contractor's "employee" for puproses of workes comp.  If the contractor did not have insurance, you can file a workers comp claim against him as well as the uninsured employers' guarantee fund.  Your best way to get medical bills paid and compensation is doing that versus a private cause of action against the homeowner.  You may also be able to sue the homeowner but you'll have to pay back comp from any recovery from suit against the home owner.