Stephen Kozlowski, M.D.
NPI 1285749390 · Rheumatology Physician · Crystal Lake, IL
Enrolled with Medicare as Practitioner - Rheumatology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Stephen Kozlowski, M.D. is a Rheumatology Physician provider in Crystal Lake, IL (NPI 1285749390).
Provider details
- NPI number
- 1285749390
- Entity type
- Individual
- Primary specialty
- Rheumatology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 036-053309 (IL)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
19 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
2 documented practice locations
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 · 1 distinct drug on file.
| Drug | Part D claims (2024) |
|---|---|
| Tramadol Hcl | 17 |
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
Additional practice locations (1)
- 2111 Midlands CtSycamore, IL 60178-3125Phone: (815) 758-0000Fax: (815) 758-0094
Registry dates
- Enumerated
- 2006-08-20
- Last updated
- 2022-07-21
Frequently asked questions
- What is Stephen Kozlowski's NPI number?
- Stephen Kozlowski's National Provider Identifier (NPI) is 1285749390, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Stephen Kozlowski's specialty?
- Stephen Kozlowski is listed in the NPPES registry with a primary specialty of Rheumatology Physician (Allopathic & Osteopathic Physicians).
- Where is Stephen Kozlowski located?
- Stephen Kozlowski's practice location on file with NPPES is 360 Station Dr, Crystal Lake, IL 60014-7978.
- What is Stephen Kozlowski's phone number?
- The practice phone number listed in the NPPES registry for Stephen Kozlowski is (815) 338-6600.
- Does Stephen Kozlowski accept Medicare?
- Stephen Kozlowski is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Stephen Kozlowski's NPI active?
- Yes — Stephen Kozlowski's NPI (1285749390) is active in the NPPES registry as of the last update on 2022-07-21.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.