WILLIAM FILBEY, AA-C appears in the CMS NPPES registry as a Anesthesiologist Assistant provider holding AA-C credentials at 600 HIGHLAND AVE, MADISON, WI, 53792, with a listed phone of (608) 263-8100. NPI 1245621051 was issued on 02/16/2015. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what FILBEY 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 prescribing data is not currently published for this NPI, which typically means the provider either wrote fewer than 11 Part D claims in the most recent reporting year, does not participate in Medicare, or practices in a specialty that rarely prescribes outpatient drugs. Absence of prescribing data is not a quality signal — many Anesthesiologist Assistant providers operate outside Part D entirely. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 77.4384/100 for the 2023 performance year (Quality 81.8371, Cost 62.1241), compared with the national average of 83.1.

Anesthesiologist Assistant is a narrow specialty nationwide, with 4,441 enrolled providers across 41 states and an average of 314 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.