Quick answers
- Where does William B. Hass see patients?
- Medicare's clinician data lists 2 practice locations, including Chesaning, MI and Owosso, MI. Call before your visit to confirm the address.
- What is William B. Hass's specialty?
- Medicare lists Optometry as the primary specialty.
- Does William B. Hass accept Medicare assignment?
- Yes. Medicare's clinician data says William B. Hass accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- What is the phone number for William B. Hass?
- (989) 845-3835, as listed in official Medicare / NPI Registry data.
- What is William B. Hass's NPI number?
- 1972598258. 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 B. Hass is enrolled with Medicare (CMS data updated 2026-10-02).
- 1180 W Broad St, 68 Robert and William Hass OptometristsChesaning, MI 48616 (989) 845‑3835
- 120 N Hickory St, 790 Robert and William Hass OptometristsOwosso, MI 48867 (989) 725‑5330
Group practices
Medicare enrollment lists William B. Hass as a member of this group (CMS data updated 2026-10-02).
- Robert and William Hass Optometrists Professional Corp3 clinicians in the group
Specialties
- Optometryprimary
Other optometrists in Michigan
Clinicians with the same Medicare primary specialty in Michigan — not a recommendation.
Clinician information
| Credential | OD |
|---|---|
| Medical school | Illinois College Of Optometry At Chicago |
| Graduation year | 1976 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1972598258 |
| 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 2026-10-02, retrieved 2026-10-29
- 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