Mark Grzesiak, RPAC
NPI 1376717272 · Physician Assistant · Mineola, NY
Enrolled with Medicare as Practitioner - Physician Assistant · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Grzesiak, RPAC is a Physician Assistant provider in Mineola, NY (NPI 1376717272).
Provider details
- NPI number
- 1376717272
- Entity type
- Individual
- Primary specialty
- Physician AssistantPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- RPAC
- Sex
- Male
- Sole proprietor
- Yes
- License
- 010785 (NY)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
18 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
31 Medicare services, 2024 (ranked within specialty)
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 methodology.
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 Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 31 | $124 |
Typical Medicare-allowed amounts for these services range $124–$124 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 22 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Ondansetronbrand: Ondansetron Odt | 105 | 79 |
| Olanzapine | 69 | 46 |
| Oxycodone Hcl | 56 | 36 |
| Apixabanbrand: Eliquis | 43 | 19 |
| Prochlorperazine Maleate | 40 | 36 |
| Potassium Chloride | 38 | 14 |
| Dexamethasone | 37 | 25 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2008-04-22
- Last updated
- 2008-04-22
Frequently asked questions
- What is Mark Grzesiak's NPI number?
- Mark Grzesiak's National Provider Identifier (NPI) is 1376717272, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Grzesiak's specialty?
- Mark Grzesiak is listed in the NPPES registry with a primary specialty of Physician Assistant (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Mark Grzesiak located?
- Mark Grzesiak's practice location on file with NPPES is 259 1st St, Mineola, NY 11501-3957.
- What is Mark Grzesiak's phone number?
- The practice phone number listed in the NPPES registry for Mark Grzesiak is (516) 663-8312.
- Does Mark Grzesiak accept Medicare?
- Mark Grzesiak is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Grzesiak's NPI active?
- Yes — Mark Grzesiak's NPI (1376717272) is active in the NPPES registry as of the last update on 2008-04-22.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.