MARK VELLEK, M.D. appears in the CMS NPPES registry as a Hematology & Oncology Physician provider holding M.D. credentials at 3131 LA CANADA ST STE 140, LAS VEGAS, NV, 89169, with a listed phone of (702) 933-9400. NPI 1063409688 was issued on 09/29/2005. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what VELLEK 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 445 prescription claims written by this provider, covering 157 Medicare beneficiaries and totaling roughly $457K in drug spend, split 8% brand-name and 92% generic by claim count, with an opioid prescribing rate of 12.1%. 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.

Hematology & Oncology Physician is a mid-sized specialty nationwide, with 11,215 enrolled providers across 54 states and an average of 847 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.