Which series is the definitive directive regarding cases referred to the Physical Evaluation Board (PEB)?

The definitive directive regarding cases referred to the Physical Evaluation Board (PEB) is SECNAVINST 1850.4. This instruction outlines the policies and procedures for the disability evaluation process within the Navy and Marine Corps, ensuring that service members are assessed fairly and consistently when it comes to medical conditions that may impact their ability to serve. It provides comprehensive guidance on the eligibility criteria, evaluation procedures, rights of the service members, and the overall workings of the PEB.

Other directives mentioned may address various aspects of personnel and medical policy, but they do not specifically focus on the entire disability evaluation process in the way that SECNAVINST 1850.4 does. This makes it the authoritative source for matters concerning the Physical Evaluation Board.