The 837 Professional and Dental Implementation Guides state that the Pay-to Provider loop is only required when the Pay-to provider is someone other than the billing provider.  When payment is to go to a medical group, the group should be identified in the Pay-to Provider Loop, Loop-ID 2010AB.  However the Remittance Advice will be sent to the Billing Provider unless overwritten by the Supervising or Rendering Provider as described in the NYS Medicaid Professional and Dental Companion Guides and Supplemental Companion Guides.