The document discusses roster billing procedures for mass immunizers administering influenza and pneumococcal vaccines to Medicare beneficiaries. It allows immunizers to submit one claim listing multiple beneficiaries receiving the same vaccine. It also describes centralized billing, which lets immunizers send all claims to a single Medicare Administrative Contractor regardless of location. Requirements for roster and centralized billing include enrollment as a mass immunizer, accepting Medicare payment as full payment, and using roster bills listing beneficiaries' information.