MATTHEW KAPTEIN, M.D. appears in the CMS NPPES registry as a Nephrology Physician provider holding M.D. credentials at 11234 ANDERSON ST, LOMA LINDA, CA, 92354, with a listed phone of (909) 558-4906. NPI 1184995094 was issued on 01/24/2012. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what KAPTEIN 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 643 prescription claims written by this provider, covering 121 Medicare beneficiaries and totaling roughly $148K in drug spend. 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 85.186/100 for the 2023 performance year (Quality 71.8166, Cost 64.5435), compared with the national average of 83.1.

Nephrology Physician is a mid-sized specialty nationwide, with 10,534 enrolled providers across 55 states and an average of 1,454 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.