WILLIAM G MATTHAEUS MD
NPI 1326039074
Internal Medicine - Hematology & Oncology in Milwaukee, WI

Q: What is William Matthaeus's NPI number?

The NPI number for William Matthaeus is 1326039074. It was assigned to this individual provider in the NPPES registry on November 2, 2005.

Q: What is William Matthaeus's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Hematology & Oncology, with taxonomy code 207RH0003X.

Q: When was this NPI record last updated?

The NPPES record for William Matthaeus was last updated on September 24, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.

Active since November 02, 2005PECOS EnrolledAccepts Medicare Assignment

1055 N MAYFAIR RD, MILWAUKEE, WI 53226(262) 857-5750 Get Directions Write a Review

NPPES record last updated: September 24, 2024. Verified against the NPPES registry weekly; last sync: November 01, 2026.

Record update history: Sep 24, 2024, Dec 2, 2021 (2 updates tracked since 2021).

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About William G Matthaeus Md NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

WILLIAM G MATTHAEUS MD (NPI 1326039074) is an individual hematology & oncology provider in Milwaukee, Wisconsin, licensed in Wisconsin (25992) and active in the NPI registry since November 2005. He is enrolled in Medicare PECOS, is affiliated with Aurora Health Care Central Inc, and is a graduate of Medical College Of Wisconsin (1983).

NPPES Registry Identity

NPI1326039074

Entity TypeIndividualMale

Primary Taxonomy207RH0003X

Provider Legal NameWILLIAM G MATTHAEUSCredential: MD

Location Address1055 N MAYFAIR RDMilwaukee, WI 53226-3436

Mailing AddressPo Box 735044Chicago, IL 60673-5044 · (800) 326-2250

Phone(262) 857-5750

Sole ProprietorNo

Medical School CMSMedical College Of WisconsinGraduated 1983

Enumeration DateNovember 2, 2005

Last NPPES UpdateSeptember 24, 20242 updates tracked since enumeration

NPPES CertifiedSeptember 24, 2024

✔ NPI 1326039074 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal Medicine · Hematology & OncologyAllopathic & Osteopathic Physicians

Taxonomy Code207RH0003X

License✔ Licensed in WI · 25992

Definition

An internist doctor of osteopathy that specializes in the treatment of the combination of hematology and oncology disorders. A doctor of osteopathy that is board eligible/certified by the American Osteopathic Board of Internal Medicine WAS able to obtain a Certificate of Special Qualifications in the field of Hematology and Oncology. The Certificate is NO longer offered.

Also ListedInternal Medicine · Hospice and Palliative MedicineTaxonomy 207RH0002X · License 25992 (WI)

1055 N MAYFAIR RD, Milwaukee, WI 53226

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Other Identifiers 2

Medicaid30850600WI

OtherP00823727WI · Rr Medicare

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Anthem Blue Cross and Blue Shield, Aspirus Health Plan, CareSource (Common Ground Healthcare) and more.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

William G Matthaeus Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID749181691

PECOS Enrollment IDI20040923000223

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

Medicare enrollment records show William Matthaeus reassigns Medicare billing to 5 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Aurora Medical Group, Inc.

3.1 mi

Obstetrics & Gynecology

8905 W LINCOLN AVE, SUITE 515
West Allis, WI 53227

Reassigned Medicare billing, Wisconsin enrollment
4,609 clinicians in this Medicare group

NPI 1457592735 (414) 328-8650

Aurora Health Care Metro, Inc.

6.1 mi

General Acute Care Hospital

2900 W OKLAHOMA AVE
Milwaukee, WI 53215

Reassigned Medicare billing, Wisconsin enrollment
297 clinicians in this Medicare group

NPI 1861447179 (414) 649-6000

Aurora Advanced Healthcare, Inc.

8.8 mi

Family Medicine

3003 W GOOD HOPE RD
Milwaukee, WI 53209

Reassigned Medicare billing, Wisconsin enrollment
1,615 clinicians in this Medicare group

NPI 1265629133 (414) 352-3100

Aurora Health Care Central, Inc.

50 mi

General Acute Care Hospital

3400 UNION AVE
Sheboygan, WI 53081

Reassigned Medicare billing, Wisconsin enrollment
34 clinicians in this Medicare group

NPI 1922053107 (920) 802-2100

Baycare Aurora, LLC

99 mi

General Acute Care Hospital

2845 GREENBRIER RD
Green Bay, WI 54311

Reassigned Medicare billing, Wisconsin enrollment
394 clinicians in this Medicare group

NPI 1255387726 (920) 288-8000

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 7

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214

This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.

247 services112 patients

Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215

This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.

149 services37 patients

Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213

This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.

120 services97 patients

New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204

This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.

28 services28 patients

Telephone medical discussion with physician, 11-20 minutes 99442

This is a service where you have a phone conversation with your doctor for 11-20 minutes. It's used for discussing health concerns, reviewing test results, or managing ongoing conditions. It's a convenient way to receive medical advice without an in-person visit.

21 services17 patients

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232

Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.

15 services12 patients

Hospital Affiliations CMS Care Compare 3

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Aurora Health Care Central Inc

Acute Care Hospitals · Sheboygan, WI

4/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number520035

Location3400 Union AveSheboygan, WI 53081 · Sheboygan County

Emergency services Birthing friendly

Aurora St Lukes Medical Center

Acute Care Hospitals · Milwaukee, WI

3/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number520138

Location2900 W Oklahoma AveMilwaukee, WI 53215 · Milwaukee County

Emergency services Birthing friendly

West Allis Memorial Hospital

Acute Care Hospitals · West Allis, WI

4/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number520139

Location8901 W Lincoln AveWest Allis, WI 53227 · Milwaukee County

Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 53226 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient

$163.24 typical visit price

range $53.90 – $163.24

Typical copayment $40.81 (range $13.47 – $40.81)

Most-billed visit code 99205

Established Patient

$95.41 typical visit price

range $17.40 – $133.76

Typical copayment $23.85 (range $4.35 – $33.44)

Most-billed visit code 99214

Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES 18

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

ONCOLOGY ALLIANCE

Non-Pharmacy Dispensing Site

1055 N MAYFAIR RD
WAUWATOSA, WI 53226

Milwaukee County (414) 479-8450

DR. SARDAR KHAN MD

Family Medicine

1055 N MAYFAIR RD
WAUWATOSA, WI 53226

Milwaukee County (414) 479-2300

DANIEL MOLINARO DO

Family Medicine

1055 N MAYFAIR RD
WAUWATOSA, WI 53226

Milwaukee County (414) 476-8450

SAVAN PANCHAL MD

Family Medicine

1055 N MAYFAIR RD
WAUWATOSA, WI 53226

Milwaukee County (414) 479-2300

KHYATI SONI D.O.

Family Medicine

1055 N MAYFAIR RD
WAUWATOSA, WI 53226

Milwaukee County (414) 479-2300

SARA J NOLAN MD

Family Medicine

1055 N MAYFAIR RD
WAUWATOSA, WI 53226

Milwaukee County (414) 476-8450

AURORA PHARMACY INC.

Pharmacy

1055 N MAYFAIR RD, SUITE 100
MILWAUKEE, WI 53226

Milwaukee County (414) 479-2500

JOHN T HAMBROOK MD

Pediatrics (Pediatric Cardiology)

1055 N MAYFAIR RD
WAUWATOSA, WI 53226

Milwaukee County (414) 479-2300

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is William Matthaeus's NPI number?

The NPI number for William Matthaeus is 1326039074. It was assigned to this individual provider in the NPPES registry on November 2, 2005.

Where is William Matthaeus located?

William Matthaeus practices at 1055 N Mayfair Rd, Milwaukee, WI 53226. The listed phone number is (262) 857-5750.

What is William Matthaeus's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Hematology & Oncology, with taxonomy code 207RH0003X.

Is William Matthaeus enrolled in Medicare?

Yes. William Matthaeus is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organizations bill Medicare for William Matthaeus's services?

According to the CMS Revalidation Reassignment List (October 2026 release), William Matthaeus reassigns Medicare benefits to 5 organizations: Aurora Medical Group, Inc. (West Allis, WI), Aurora Health Care Metro, Inc. (Milwaukee, WI), Aurora Advanced Healthcare, Inc. (Milwaukee, WI), Aurora Health Care Central, Inc. (Sheboygan, WI) and Baycare Aurora, LLC (Green Bay, WI). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for William Matthaeus's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does William Matthaeus accept?

Health plans from Anthem Blue Cross and Blue Shield, Aspirus Health Plan, CareSource (Common Ground Healthcare), HealthPartners and Network Health and 2 other insurers list William Matthaeus as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

Is William Matthaeus affiliated with any hospitals?

According to CMS data, William Matthaeus is affiliated with Aurora Health Care Central Inc, Aurora St Lukes Medical Center and West Allis Memorial Hospital.

When was this NPI record last updated?

The NPPES record for William Matthaeus was last updated on September 24, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.