Robert Williams, MD
NPI 1619909868 · Internal Medicine Physician · New Berlin, WI
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Robert Williams, MD is a Internal Medicine Physician provider in New Berlin, WI (NPI 1619909868).
Provider details
- NPI number
- 1619909868
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 43644 (WI)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
19 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
556 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) |
|---|---|---|
| Anticoagulant Management of Patient Taking Warfarin93793 | 169 | $11 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 155 | $121 |
| Blood Test, Clotting Time85610 | 144 | $4 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 52 | $122 |
| Administration of Influenza Virus VaccineG0008 | 20 | $30 |
| Admn Sarscov2 Vacc 1 Dose90480 | 16 | $41 |
Typical Medicare-allowed amounts for these services range $4–$122 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, 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 · 74 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Lisinopril | 245 | 58 |
| Atorvastatin Calcium | 179 | 50 |
| Pravastatin Sodium | 166 | 47 |
| Simvastatin | 153 | 35 |
| Levothyroxine Sodium | 150 | 28 |
| Amlodipine Besylate | 123 | 35 |
| Hydrochlorothiazide | 123 | 36 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-07-07
- Last updated
- 2021-11-23
- Certified
- 2021-11-23
Frequently asked questions
- What is Robert Williams's NPI number?
- Robert Williams's National Provider Identifier (NPI) is 1619909868, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Robert Williams's specialty?
- Robert Williams is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Robert Williams located?
- Robert Williams's practice location on file with NPPES is 14555 W National Ave, New Berlin, WI 53151-4494.
- What is Robert Williams's phone number?
- The practice phone number listed in the NPPES registry for Robert Williams is (262) 827-3636.
- Does Robert Williams accept Medicare?
- Robert Williams is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Robert Williams's NPI active?
- Yes — Robert Williams's NPI (1619909868) is active in the NPPES registry as of the last update on 2021-11-23.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.