Mercedes Williams, MD
NPI 1558866079 · Obstetrics & Gynecology Physician · West Allis, WI
Enrolled with Medicare as Practitioner - Obstetrics/Gynecology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mercedes Williams, MD is a Obstetrics & Gynecology Physician provider in West Allis, WI (NPI 1558866079).
Provider details
- NPI number
- 1558866079
- Entity type
- Individual
- Primary specialty
- Obstetrics & Gynecology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Female
- Sole proprietor
- No
- License
- 74044 (WI)
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 tenure38% of score
8 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.
Practice location
Mailing address
Additional practice locations (1)
- 8901 W Lincoln AveWest Allis, WI 53227-2409Phone: (414) 328-6000
Registry dates
- Enumerated
- 2018-03-27
- Last updated
- 2025-07-19
- Certified
- 2025-07-19
Frequently asked questions
- What is Mercedes Williams's NPI number?
- Mercedes Williams's National Provider Identifier (NPI) is 1558866079, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mercedes Williams's specialty?
- Mercedes Williams is listed in the NPPES registry with a primary specialty of Obstetrics & Gynecology Physician (Allopathic & Osteopathic Physicians).
- Where is Mercedes Williams located?
- Mercedes Williams's practice location on file with NPPES is 8905 W Lincoln Ave Ste 515, West Allis, WI 53227-2470.
- What is Mercedes Williams's phone number?
- The practice phone number listed in the NPPES registry for Mercedes Williams is (414) 328-8650.
- Does Mercedes Williams accept Medicare?
- Mercedes Williams is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mercedes Williams's NPI active?
- Yes — Mercedes Williams's NPI (1558866079) is active in the NPPES registry as of the last update on 2025-07-19.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.