I went to a chiropractor for shoulder and arm pain. We both knew I would need surgery and wanted to be in the best s hape possible going in. I had surgery and my surgeon gave me a referral for Physical Therapy. My insurance company denied this referral because the chiropractor had billed for both Chiro and PT and used up all my benefits-knowing I needed surgery and would have course need PT after surgery. How can a Chiropractor become a PT for billing purposes?

Something is wrong. Your insurance company needs to be told that the chiro work was before surgery and now the doctor is sending you for PT after surgery -- two separate situations. Will the dr's office straighten this out for you? Or can you do it?

I would guess that you have a limited health insurance policy that only pays for a limited number of PT visits during a calendar year, or a limited amout of money?
Is this the case ?

But yes the chiropractor normally bills insurance for his service doing adjustment, and then if other service is done, that is billed out as PT. This is normal and how their billing works.

Your ability to pay or not pay, is not the chiropractor concern, he offers you the service you need at that time. The chiropractor would assume you had figured out how to pay for it all