Grazyna Siwy, M.D.
NPI 1447498910 · Internal Medicine Physician · Chicago, IL
Enrolled with Medicare as Practitioner - General Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Grazyna Siwy, M.D. is a Internal Medicine Physician provider in Chicago, IL (NPI 1447498910).
Provider details
- NPI number
- 1447498910
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Female
- Sole proprietor
- Yes
- License
- 036122386 (IL)
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
17 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
218 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 | 178 | $133 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 21 | $81 |
| Anticoagulant Management of Patient Taking Warfarin93793 | 19 | $12 |
Typical Medicare-allowed amounts for these services range $12–$133 (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 · 49 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 222 | 79 |
| Amlodipine Besylate | 199 | 66 |
| Hydrochlorothiazide | 145 | 45 |
| Albuterol Sulfatebrand: Albuterol Sulfate Hfa | 90 | 25 |
| Enalapril Maleate | 88 | 29 |
| Losartan Potassium | 84 | 31 |
| Metformin Hcl |
Practice location
Mailing address
Registry dates
- Enumerated
- 2009-01-22
- Last updated
- 2021-04-30
- Certified
- 2021-04-30
Frequently asked questions
- What is Grazyna Siwy's NPI number?
- Grazyna Siwy's National Provider Identifier (NPI) is 1447498910, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Grazyna Siwy's specialty?
- Grazyna Siwy is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Grazyna Siwy located?
- Grazyna Siwy's practice location on file with NPPES is 1901 W Harrison St, Chicago, IL 60612-3714.
- What is Grazyna Siwy's phone number?
- The practice phone number listed in the NPPES registry for Grazyna Siwy is (312) 864-6000.
- Does Grazyna Siwy accept Medicare?
- Grazyna Siwy is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Grazyna Siwy's NPI active?
- Yes — Grazyna Siwy's NPI (1447498910) is active in the NPPES registry as of the last update on 2021-04-30.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.