CHRISTOPHER DIEHL, O.D. appears in the CMS NPPES registry as a Optometrist provider holding O.D. credentials at 4405 HAMILTON BLVD, SIOUX CITY, IA, 51104, with a listed phone of (712) 239-3937. NPI 1053607515 was issued on 06/23/2011. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what DIEHL 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 2,903 prescription claims written by this provider, covering 471 Medicare beneficiaries and totaling roughly $356K in drug spend, split 33% brand-name and 67% 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 86.1064/100 for the 2023 performance year (Quality 100, Cost 53.688), compared with the national average of 83.1.

Optometrist is a high-volume specialty nationwide, with 60,463 enrolled providers across 56 states and an average of 257 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.