If a chiropractor got paid 100% by my Medpay, Can he get paid again by the 3rd party insurance?

The other insurance company, liable carrier, will require medical bills and records to evaluate your claim. Depending on your state, will determine how the rest of the claim is paid. If your insurance carrier, Allstate, is allowed subrogation rights by law, then they will put the at fault carrier on notice. When the claim is settled, they will issue a check to Allstate for their interest and you will receive the remaining amount. If any other medical providers have not been paid and they’ve filed a lein against the settlement, the at fault carrier will also issue them a check seperately. If no other medical providers have filed leins, then demand the insurance carrier to pay you directly for unpaid bills as by law, it is your responsibility.
Now, in some states, your medical provider can get paid by the MED PAY policy and the at fault party can also pay you for the medical bills. But to answer your question, the medical provider can’t get paid twice for the same work. Remember, if no lein has been filed, then the at fault party either pays you or your insurance carrier (subrogation). Have the at fault party provide you with copies of all leins filed on your behalf. If you have any questions, contact Allstate and they could clarify any questions you might have.