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John B. Williamson, PHD

Psychologists (Clinical Neuropsychologist)

  • Medicare participating

At a glance

Years since graduation
22
In the NPI registry since
2011
Medicare patients seen, 2024
25

The NPI date is when this clinician registered for a National Provider Identifier, the billing number used on health claims. It is not a license, graduation or board-certification date. What an NPI is

Education and training

  • 2011Registered with an NPI (national billing number; not a license date)

Medicare’s Care Compare data doesn’t list this clinician’s medical school. Undergraduate school, residency, fellowship, licensing exams and board certification aren’t in public federal data. Board certification can be confirmed with the certifying board (ABMS member boards for MDs, AOA boards for DOs).

Specialties and state licenses

  • Clinical Neuropsychologist primary
    FL license PY8262

As reported to the NPI registry. To confirm a license is current, check the state medical board.

Map: Psychologists per capita by county →

Medicare patients and services

Medicare patients, 2024
25
Services billed
235
Patients’ average age
71
Most frequent Medicare services, 2023
ServiceTimesPatients
Administration of psychological or neuropsychological test by technician, each additional 30 minutes15129
Evaluation of neuropsychological test, each additional hour3029
Evaluation of neuropsychological test, first hour2929
Administration of psychological or neuropsychological test by technician, first 30 minutes2929
Psychiatric diagnostic evaluation2626

Medicare fee-for-service only. CMS leaves out services billed for fewer than 11 patients. These figures describe a practice’s Medicare work; they aren’t a measure of quality.

Other Psychologists clinicians in Gainesville

Sources

NPI registry (CMS NPPES, November 2026; record last updated January 18, 2012), Medicare Care Compare, Medicare Physician & Other Practitioners (2024), Medicare Part D Prescribers (2024) and Open Payments (2025). Information is self-reported or billed data and may be out of date; call before visiting.

NPI 1215224977. Official NPI registry record (opens in a new tab). Clinicians can correct their information in NPPES; changes appear here after our next monthly update.