DENIS O'BRIEN, MD appears in the CMS NPPES registry as a Orthopaedic Surgery Physician provider holding MD credentials at 3414 OLANDWOOD CT, OLNEY, MD, 20832, with a listed phone of (301) 774-0500. NPI 1427053339 was issued on 06/16/2005. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what O'BRIEN 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 records for calendar year 2023 show 557 prescription claims written by this provider, covering 280 Medicare beneficiaries and totaling roughly $4K in drug spend, with an opioid prescribing rate of 22.3%. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Orthopaedic Surgery Physician is a mid-sized specialty nationwide, with 25,781 enrolled providers across 56 states and an average of 324 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.