Quick answers
- Does Trisha L. Zylstra accept Medicare assignment?
- Yes. Medicare's clinician data says Trisha L. Zylstra 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 Trisha L. Zylstra see?
- In 2024, CMS data shows 23 Original Medicare patients and 32 services for Trisha L. Zylstra. This counts Original Medicare only and measures volume, not quality.
- What is Trisha L. Zylstra's NPI number?
- 1134223779. 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 Trisha L. Zylstra, 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 | 23 |
|---|---|
| Services billed to Medicare | 32 |
| Different services or procedures | 6 |
| Participating Medicare provider | Yes |
| Average age of these patients | 65 |
Practice locations
Addresses where Trisha L. Zylstra is enrolled with Medicare (CMS data updated October 2, 2026).
- 10047 Crossroad Ct SECaledonia, MI 49316 (616) 685‑8850
- 200 Jefferson Ave SEGrand Rapids, MI 49503 (616) 685‑5000
Group practices
Medicare enrollment lists Trisha L. Zylstra as a member of this group (CMS data updated October 2, 2026).
- Advantage Health/Saint Mary's Medical Group505 clinicians in the group
Specialties
- Obstetrics/Gynecologyprimary
Other OB-GYNs in Caledonia
Clinicians with the same Medicare primary specialty in Caledonia, MI — not a recommendation.
Other clinicians in Advantage Health/Saint Mary's Medical Group
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Michigan State University College Of Human Medicine |
| Graduation year | 2002 (24 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1134223779 |
| 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