William Matthaeus, MD
NPI 1326039074 · Hematology & Oncology Physician · Milwaukee, WI
Enrolled with Medicare as Practitioner - Hematology/Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Matthaeus, MD is a Hematology & Oncology Physician provider in Milwaukee, WI (NPI 1326039074).
Provider details
- NPI number
- 1326039074
- Entity type
- Individual
- Primary specialty
- Hematology & Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 25992 (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
20 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
592 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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 247 | $88 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 149 | $133 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 120 | $60 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 | 28 | $123 |
| Telephone Medical Discussion With Physician, 11-20 Minutes99442 | 21 | $61 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 40 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Anastrozole | 172 | 40 |
| Prochlorperazine Maleate | 88 | 37 |
| Letrozole | 84 | 21 |
| Prednisone | 62 | 17 |
| Apixabanbrand: Eliquis | 55 | 11 |
| Palbociclibbrand: Ibrance | 55 | — |
| Rivaroxabanbrand: Xarelto | 47 | 11 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2005-11-02
- Last updated
- 2024-09-24
- Certified
- 2024-09-24
Frequently asked questions
- What is William Matthaeus's NPI number?
- William Matthaeus's National Provider Identifier (NPI) is 1326039074, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Matthaeus's specialty?
- William Matthaeus is listed in the NPPES registry with a primary specialty of Hematology & Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is William Matthaeus located?
- William Matthaeus's practice location on file with NPPES is 1055 N Mayfair Rd, Milwaukee, WI 53226-3436.
- What is William Matthaeus's phone number?
- The practice phone number listed in the NPPES registry for William Matthaeus is (262) 857-5750.
- Does William Matthaeus accept Medicare?
- William Matthaeus is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Matthaeus's NPI active?
- Yes — William Matthaeus's NPI (1326039074) is active in the NPPES registry as of the last update on 2024-09-24.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.