Quick answers
- Does William J. Greenberg accept Medicare assignment?
- Yes. Medicare's clinician data says William J. Greenberg 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.
- What is William J. Greenberg's NPI number?
- 1306816491. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Practice locations
Addresses where William J. Greenberg is enrolled with Medicare (CMS data updated October 2, 2026).
- 11 Friends Ln, Suite 101aNewtown, PA 18940 (215) 550‑6136
- 395 Hwy 33Mercerville, NJ 08619 (609) 586‑0273
- 498 Monmouth RdMillshore Twsp, NJ 08510 (609) 259‑2221
Group practices
Medicare enrollment lists William J. Greenberg as a member of this group (CMS data updated October 2, 2026).
- Mark W Beyer LLC2 clinicians in the group
Specialties
- Optometryprimary
Other optometrists in Newtown
Clinicians with the same Medicare primary specialty in Newtown, PA — not a recommendation.
Other clinicians in Mark W Beyer LLC
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | OD |
|---|---|
| Optometry school | Pennsylvania College Of Optometry |
| Graduation year | 1977 (49 years since optometry school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1306816491 |
| 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
- 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