COLLEEN O'LEARY, RN, AOCNS appears in the CMS NPPES registry as a Oncology Registered Nurse provider holding RN, AOCNS credentials at 25 S EUCLID AVE, VILLA PARK, IL, 60181, with a listed phone of (773) 965-4727. NPI 1457658973 was issued on 02/18/2011. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what O'LEARY 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 Oncology Registered Nurse providers operate outside Part D entirely.

Oncology Registered Nurse is a narrow specialty nationwide, with 857 enrolled providers across 50 states and an average of 555 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.