GIAC CHAN NGUYEN TAN, M.D. appears in the CMS NPPES registry as a Undersea and Hyperbaric Medicine (Emergency Medicine) Physician provider holding M.D. credentials at 171 GRANDVIEW AVE, WATERBURY, CT, 06708, with a listed phone of (203) 694-8200. NPI 1962585042 was issued on 10/23/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what NGUYEN TAN 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 737 prescription claims written by this provider, covering 429 Medicare beneficiaries and totaling roughly $12K in drug spend, split 6% brand-name and 94% generic by claim count, with an opioid prescribing rate of 4.6%. 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 92.6187/100 for the 2023 performance year (Quality 84.1793, Cost 65.2254), compared with the national average of 83.1.

Undersea and Hyperbaric Medicine (Emergency Medicine) Physician is a narrow specialty nationwide, with 201 enrolled providers across 43 states and an average of 367 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.