Gregory Siwek, MD
NPI 1437125317 · Infectious Disease Physician · Saint Paul, MN
Enrolled with Medicare as Practitioner - Infectious Disease · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Gregory Siwek, MD is a Infectious Disease Physician provider in Saint Paul, MN (NPI 1437125317).
Provider details
- NPI number
- 1437125317
- Entity type
- Individual
- Primary specialty
- Infectious Disease PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 43054 (MN)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
20 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
692 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) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 459 | $112 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 95 | $161 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 63 | $118 |
| Complete Blood Cell Count (red Cells, White Blood Cell, Platelets), Automated Test and Automated Differential White Blood Cell Count85025 | 40 | $7 |
| Insertion of Needle Into Vein for Collection of Blood Sample36415 | 35 | $8 |
Typical Medicare-allowed amounts for these services range $7–$161 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, 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 · 17 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Bictegrav/Emtricit/Tenofov Alabrand: Biktarvy | 147 | 16 |
| Dolutegravir Sodiumbrand: Tivicay | 69 | — |
| Emtricitabine/Tenofov Alafenambrand: Descovy | 64 | — |
| Ceftriaxone Sodiumbrand: Ceftriaxone | 39 | — |
| Cephalexin | 33 | 13 |
| Ertapenem Sodiumbrand: Ertapenem | 27 | — |
| Elviteg/Cob/Emtri/Tenof Alafenbrand: Genvoya |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-02-28
- Last updated
- 2024-06-20
- Certified
- 2024-06-20
Frequently asked questions
- What is Gregory Siwek's NPI number?
- Gregory Siwek's National Provider Identifier (NPI) is 1437125317, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Gregory Siwek's specialty?
- Gregory Siwek is listed in the NPPES registry with a primary specialty of Infectious Disease Physician (Allopathic & Osteopathic Physicians).
- Where is Gregory Siwek located?
- Gregory Siwek's practice location on file with NPPES is 401 Phalen Blvd, Saint Paul, MN 55130-5302.
- What is Gregory Siwek's phone number?
- The practice phone number listed in the NPPES registry for Gregory Siwek is (651) 254-7820.
- Does Gregory Siwek accept Medicare?
- Gregory Siwek is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Gregory Siwek's NPI active?
- Yes — Gregory Siwek's NPI (1437125317) is active in the NPPES registry as of the last update on 2024-06-20.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.