Martin Greydanus, M.D.
NPI 1043215544 · Specialist · Grand Rapids, MI
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Martin Greydanus, M.D. is a Specialist provider in Grand Rapids, MI (NPI 1043215544).
Provider details
- NPI number
- 1043215544
- Entity type
- Individual
- Primary specialty
- SpecialistOther Service Providers
- Credential
- M.D.
- Sex
- Male
- License
- 4301048500 (MI)
Specialties & taxonomies
Other Service Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
21 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 3 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Omeprazole | 27 | — |
| Sodium Chloride/Nahco3/Kcl/Pegbrand: Peg 3350-Electrolyte | 15 | 15 |
| Azathioprine | 14 | — |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Registry dates
- Enumerated
- 2005-06-20
- Last updated
- 2007-07-08
Frequently asked questions
- What is Martin Greydanus's NPI number?
- Martin Greydanus's National Provider Identifier (NPI) is 1043215544, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Martin Greydanus's specialty?
- Martin Greydanus is listed in the NPPES registry with a primary specialty of Specialist (Other Service Providers).
- Where is Martin Greydanus located?
- Martin Greydanus's practice location on file with NPPES is 310 Lafayette Ave Se, Grand Rapids, MI 49503-4693.
- What is Martin Greydanus's phone number?
- The practice phone number listed in the NPPES registry for Martin Greydanus is (616) 752-6525.
- Does Martin Greydanus accept Medicare?
- Martin Greydanus is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Martin Greydanus's NPI active?
- Yes — Martin Greydanus's NPI (1043215544) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.