Sean Williams, M.D.
NPI 1255712626 · Emergency Medicine Physician · Chicago, IL
Enrolled with Medicare as Practitioner - Emergency Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Sean Williams, M.D. is a Emergency Medicine Physician provider in Chicago, IL (NPI 1255712626).
Provider details
- NPI number
- 1255712626
- Entity type
- Individual
- Primary specialty
- Emergency Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 036144052 (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
11 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
3 documented practice locations
- Medicare service volume (vs. specialty peers)28% of score
33 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) |
|---|---|---|
| Emergency Department Visit With High Level of Medical Decision Making99285 | 19 | $186 |
| Electrocardiogram (ecg) 1 to 3 Leads With Review By Physician Only93042 | 14 | $7 |
Typical Medicare-allowed amounts for these services range $7–$186 (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.
Practice location
Mailing address
Additional practice locations (2)
- 7435 W Talcott AveChicago, IL 60631-3707Phone: (773) 774-8000
- 7435 W Talcott AveChicago, IL 60631-3707Phone: (773) 774-8000
Registry dates
- Enumerated
- 2015-06-11
- Last updated
- 2021-03-18
- Certified
- 2021-03-18
Frequently asked questions
- What is Sean Williams's NPI number?
- Sean Williams's National Provider Identifier (NPI) is 1255712626, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Sean Williams's specialty?
- Sean Williams is listed in the NPPES registry with a primary specialty of Emergency Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Sean Williams located?
- Sean Williams's practice location on file with NPPES is 5645 W Addison St, Chicago, IL 60634-4403.
- What is Sean Williams's phone number?
- The practice phone number listed in the NPPES registry for Sean Williams is (773) 794-8383.
- Does Sean Williams accept Medicare?
- Sean Williams is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Sean Williams's NPI active?
- Yes — Sean Williams's NPI (1255712626) is active in the NPPES registry as of the last update on 2021-03-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.