Michael Grenis, MD
NPI 1669546834 · Orthopaedic Surgery Physician · Princeton, NJ
Enrolled with Medicare as Practitioner - Orthopedic Surgery · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Michael Grenis, MD is a Orthopaedic Surgery Physician provider in Princeton, NJ (NPI 1669546834).
Provider details
- NPI number
- 1669546834
- Entity type
- Individual
- Primary specialty
- Orthopaedic Surgery PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- MD442362 (PA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
2,241 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. 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 .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 647 | $104 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 436 | $147 |
| Injection Into Tendon Or Ligament20550 | 226 | $66 |
| X-Ray of Wrist, Minimum of 3 Views73110 | 182 | $49 |
| X-Ray of Hand, Minimum of 3 Views73130 | 182 | $44 |
| New Patient Office Or Other Outpatient Visit With Low Level of Medical Decision Making, If Using Time, 30 Minutes Or More99203 | 137 |
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 |
|---|---|---|
| Oxycodone Hcl/Acetaminophenbrand: Oxycodone-Acetaminophen | 69 | 67 |
| Meloxicam | 24 | 17 |
| Cephalexin | 11 | — |
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.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$50 across 2 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-11-20
- Last updated
- 2019-09-30
Frequently asked questions
- What is Michael Grenis's NPI number?
- Michael Grenis's National Provider Identifier (NPI) is 1669546834, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Michael Grenis's specialty?
- Michael Grenis is listed in the NPPES registry with a primary specialty of Orthopaedic Surgery Physician (Allopathic & Osteopathic Physicians).
- Where is Michael Grenis located?
- Michael Grenis's practice location on file with NPPES is 325 Princeton Ave, Princeton, NJ 08540-1617.
- What is Michael Grenis's phone number?
- The practice phone number listed in the NPPES registry for Michael Grenis is (609) 924-8131.
- Does Michael Grenis accept Medicare?
- Michael Grenis is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Michael Grenis's NPI active?
- Yes — Michael Grenis's NPI (1669546834) is active in the NPPES registry as of the last update on 2019-09-30.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.