Military Medical Support Office at Defense Health Agency, Great Lakes

1-888-647-6676: All services but Coast Guard
757-628-4379: Coast Guard

https://health.mil/Military-Health-Topics/Access-Cost-Quality-and-Safety/TRICARE-Health-Plan/MMSO
The Military Medical Support Office at Defense Health Agency, Great Lakes serves as the customer service point of contact for medical/dental case management for services outside of a military hospital or clinic.
Services provided are for TRICARE Prime Remote-eligible and National Guard and Reserve service members within the 50 United States and District of Columbia.
Specified Authorization Staff (SAS) is the uniformed service office responsible for coordinating civilian health care for service members participating in TPR.