MARK HARRISON, MD appears in the CMS NPPES registry as a Infectious Disease Physician provider holding MD credentials at 1234 NAPIER AVE, SAINT JOSEPH, MI, 49085, with a listed phone of (269) 471-1700. NPI 1346278108 was issued on 06/29/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what HARRISON 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 185 prescription claims written by this provider, covering 63 Medicare beneficiaries and totaling roughly $14K in drug spend, split 19% brand-name and 81% 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 100/100 for the 2023 performance year (Quality 87.5432), compared with the national average of 83.1.

Infectious Disease Physician is a mid-sized specialty nationwide, with 8,292 enrolled providers across 54 states and an average of 816 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.