CHIWAI CHAN, D.O. appears in the CMS NPPES registry as a Pain Medicine Physician provider holding D.O. credentials at 11160 WARNER AVE, FOUNTAIN VALLEY, CA, 92708, with a listed phone of (714) 424-9300. NPI 1629051529 was issued on 11/23/2005. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what CHAN 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 1,011 prescription claims written by this provider, covering 338 Medicare beneficiaries and totaling roughly $40K in drug spend, split 5% brand-name and 95% generic by claim count, with an opioid prescribing rate of 61.5%. 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.

Pain Medicine Physician is a narrow specialty nationwide, with 951 enrolled providers across 49 states and an average of 2,078 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.