DIANA CHAO, MD appears in the CMS NPPES registry as a Glaucoma Specialist (Ophthalmology) Physician provider holding MD credentials at 7232 ROSEMEAD BLVD STE 202, SAN GABRIEL, CA, 91775, with a listed phone of (626) 534-6698. NPI 1528320298 was issued on 06/08/2012. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what CHAO 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 3,695 prescription claims written by this provider, covering 539 Medicare beneficiaries and totaling roughly $348K in drug spend, split 38% brand-name and 62% generic by claim count. 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.

Glaucoma Specialist (Ophthalmology) Physician is a narrow specialty nationwide, with 354 enrolled providers across 42 states and an average of 2,962 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.