Quick answers
- Does Mariann M. Channell accept Medicare assignment?
- Yes. Medicare's clinician data says Mariann M. Channell 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 Mariann M. Channell see?
- In 2024, CMS data shows 673 Original Medicare patients and 2,290 services for Mariann M. Channell. This counts Original Medicare only and measures volume, not quality.
- What is Mariann M. Channell's NPI number?
- 1225030596. 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 Mariann M. Channell, 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 | 673 |
|---|---|
| Services billed to Medicare | 2,290 |
| Different services or procedures | 27 |
| Participating Medicare provider | Yes |
| Average age of these patients | 77 |
Most frequent services
- Established patient problem focused exam of visual system (92012)442 services
- Established patient complete exam of visual system (92014)431 services
- Photography of the retina (92250)411 services
- Exam of visual field with extended testing (92083)181 services
- Imaging of optic nerve (92133)181 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High blood pressure75%
- High cholesterol75%
- Arthritis45%
- Diabetes29%
- Ischemic heart disease28%
- Chronic kidney disease25%
Practice locations
Addresses where Mariann M. Channell is enrolled with Medicare (CMS data updated October 2, 2026).
- 21711 Greater Mack AveSaint Clair Shores, MI 48080 (810) 774‑0393
Group practices
Medicare enrollment lists Mariann M. Channell as a member of this group (CMS data updated October 2, 2026).
- Richard C Mertz Jr MD PC5 clinicians in the group
Specialties
- Ophthalmologyprimary
Other ophthalmologists in Saint Clair Shores
Clinicians with the same Medicare primary specialty in Saint Clair Shores, MI — not a recommendation.
Other clinicians in Richard C Mertz Jr MD PC
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Wayne State University School Of Medicine |
| Graduation year | 1980 (46 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1225030596 |
| 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