Cassidy Williams, DO
NPI 1578211140 · Surgery Physician · Chicago, IL
Enrolled with Medicare as Order and Referring Only - General Surgery · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Cassidy Williams, DO is a Surgery Physician provider in Chicago, IL (NPI 1578211140).
Provider details
- NPI number
- 1578211140
- Entity type
- Individual
- Primary specialty
- Surgery PhysicianAllopathic & Osteopathic Physicians
- Credential
- DO
- Sex
- Female
- Sole proprietor
- No
- License
- 125.082539 (IL)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Student, Health Care
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
4 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
1 documented practice location
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
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.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$496 across 4 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2022-03-14
- Last updated
- 2023-09-20
- Certified
- 2023-09-20
Frequently asked questions
- What is Cassidy Williams's NPI number?
- Cassidy Williams's National Provider Identifier (NPI) is 1578211140, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Cassidy Williams's specialty?
- Cassidy Williams is listed in the NPPES registry with a primary specialty of Surgery Physician (Allopathic & Osteopathic Physicians).
- Where is Cassidy Williams located?
- Cassidy Williams's practice location on file with NPPES is 600 S Paulina St, Chicago, IL 60612-3806.
- What is Cassidy Williams's phone number?
- The practice phone number listed in the NPPES registry for Cassidy Williams is (312) 942-7100.
- Does Cassidy Williams accept Medicare?
- Cassidy Williams is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Cassidy Williams's NPI active?
- Yes — Cassidy Williams's NPI (1578211140) is active in the NPPES registry as of the last update on 2023-09-20.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.