CHRISTOS MASTROYANNIS, MD FACOG appears in the CMS NPPES registry as a Reproductive Endocrinology Physician provider holding MD FACOG credentials at 8501 ARLINGTON BLVD, FAIRFAX, VA, 22031, with a listed phone of (877) 449-0400. NPI 1629009543 was issued on 07/06/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what MASTROYANNIS most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D prescribing data is not currently published for this NPI, which typically means the provider either wrote fewer than 11 Part D claims in the most recent reporting year, does not participate in Medicare, or practices in a specialty that rarely prescribes outpatient drugs. Absence of prescribing data is not a quality signal — many Reproductive Endocrinology Physician providers operate outside Part D entirely.

Reproductive Endocrinology Physician is a narrow specialty nationwide, with 1,413 enrolled providers across 48 states and an average of 104 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline. Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist — always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.