MARSDEN BLOIS, MD appears in the CMS NPPES registry as a Advanced Heart Failure and Transplant Cardiology Physician provider holding MD credentials at 4743 ARAPAHOE AVE, BOULDER, CO, 80303, with a listed phone of (303) 442-2395. NPI 1215938683 was issued on 08/09/2005. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what BLOIS 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 4,665 prescription claims written by this provider, covering 532 Medicare beneficiaries and totaling roughly $1.5 million in drug spend, split 21% brand-name and 79% 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.

Advanced Heart Failure and Transplant Cardiology Physician is a narrow specialty nationwide, with 510 enrolled providers across 48 states and an average of 1,762 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.