Quick answers
- Does William B. Gunn Jr. accept Medicare assignment?
- Yes. Medicare's clinician data says William B. Gunn Jr. accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does William B. Gunn Jr. see?
- In 2024, CMS data shows 12 Original Medicare patients and 102 services for William B. Gunn Jr.. This counts Original Medicare only and measures volume, not quality.
- What is William B. Gunn Jr.'s NPI number?
- 1053347971. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for William B. Gunn Jr., data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 12 |
|---|---|
| Services billed to Medicare | 102 |
| Different services or procedures | 3 |
| Participating Medicare provider | Yes |
| Average age of these patients | 72 |
Most frequent services
- Psychotherapy, 1 hour (90837)99 services
Practice locations
Addresses where William B. Gunn Jr. is enrolled with Medicare (CMS data updated October 2, 2026).
- 426 State StPortsmouth, NH 03801 (978) 712‑9155
Specialties
- Clinical Psychologistprimary
Find other clinicians: Clinical Psychologist, New Hampshire →
Other clinical psychologists in Portsmouth
Clinicians with the same Medicare primary specialty in Portsmouth, NH — not a recommendation.
Clinician information
| Credential | CP |
|---|---|
| Graduation year | 1986 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1053347971 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians