Participating Provider Enrollments – ACO / PHO Relationships

Updated 11/5/2025

This bulletin serves as a reminder of Meridian’s governance rules related to Participating (PAR) relationships, particularly as they pertain to Accountable Care Organizations (ACOs) and Physician Hospital Organizations (PHOs). This is not a new policy, but a clarification and reinforcement of existing standards following recent audits and data stabilization efforts.

A PAR relationship is defined by Taxpayer Identification Number (TIN). An individual TIN cannot participate in more than one Meridian relationship.

During recent auditing and stabilization of provider data on behalf of our relationship we want to gently remind our participating providers of the governance rules for participation in Meridian’s network:

• Direct Fee-for-Service Relationships:
  • If you have a direct-fee-for-service contract with Meridian, you may not also participate in a PHO or ACO relationship.
    • If Meridian’s provider data team identifies that a conflicting relationship exists (i.e., both a direct and a PHO/ACO arrangement), we will notify the PHO/ACO and request removal of your TIN from their participation rosters.
    • Direct Relationship Conflict: If a Provider is already active with a direct practitioner contract with Meridian, they cannot participate in a PHO practitioner contract or roster without first terming their direct relationship with Meridian.
• PHO/ACO-Only Participation
  • If you do not have a direct relationship with Meridian, and instead participate through a PHO or ACO, you may only participate in one PHO or ACO arrangement.
    • If our provider data team identifies that your TIN is associated with more than one PHO/ ACO, we will contact the PHO/ACO leads and request attestation regarding which relationship you wish to maintain.
    •  PHO/ACO to PHO/ACO Conflict: If a Provider is already participating in a PHO practitioner contract/roster with Meridian, attestation from the Provider is required to transition into a new PHO roster for participation. A Provider cannot participate in more than one PHO practitioner contract/roster with Meridian. Provider will need to attest to the relationship and provide this attestation to the PHO of their choice and Meridian as applicable. 
    • Effective Date: Changes related to PHO-to-PHO transitions will be effective 30 days from the date Meridian receives the provider’s attestation.

If you have any questions regarding your relationship with Meridian, please contact us via our Provider Relations Inquiry Form