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Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

WILLIAM CHRISTIAN AHRENHOLZ PA
NPI 1043968001
Physician Assistant in Chicago, IL

Active since March 17, 2022PECOS EnrolledAccepts Medicare Assignment
676 N SAINT CLAIR ST STE 2100, CHICAGO, IL 60611(312) 695-1800(312) 695-4741 Get Directions Write a Review

NPPES record last updated: July 10, 2026. Verified against the NPPES registry weekly; last sync: August 02, 2026.

Record update history: Jul 10, 2026, Aug 31, 2022, Aug 22, 2022 (3 updates tracked since 2022).

About William Christian Ahrenholz Pa NPPES

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

WILLIAM CHRISTIAN AHRENHOLZ PA (NPI 1043968001) is an individual physician assistant in Chicago, Illinois, licensed in Illinois (085009068) and active in the NPI registry since March 2022. He is enrolled in Medicare PECOS, is affiliated with Mt Sinai Hospital Medical Center, and is a graduate of Other (2022).

NPPES Registry Identity

NPI1043968001
Entity TypeIndividualMale
Primary Taxonomy363A00000X
Provider Legal NameWILLIAM CHRISTIAN AHRENHOLZCredential: PA
Location Address676 N SAINT CLAIR ST STE 2100Chicago, IL 60611-2993
Mailing Address676 N Saint Clair St Ste 2100Chicago, IL 60611-2993 · (312) 695-1800 · Fax (312) 695-4741
Phone(312) 695-1800
Fax(312) 695-4741
Sole ProprietorYes
Medical School CMSOtherGraduated 2022
Enumeration DateMarch 17, 2022
Last NPPES UpdateJuly 10, 20263 updates tracked since enumeration
NPPES CertifiedJuly 10, 2026
✔ NPI 1043968001 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyPhysician AssistantPhysician Assistants & Advanced Practice Nursing Providers
Taxonomy Code363A00000X
License✔ Licensed in IL · 085009068
Definition
A physician assistant is a person who has successfully completed an accredited education program for physician assistant, is licensed by the state and is practicing within the scope of that license. Physician assistants are formally trained to perform many of the routine, time-consuming tasks a physician can do. In some states, they may prescribe medications. They take medical histories, perform physical exams, order lab tests and x-rays, and give inoculations. Most states require that they work under the supervision of a physician.
676 N SAINT CLAIR ST STE 2100, Chicago, IL 60611
Open in Google Maps ↗

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Ambetter from Home State Health, Ambetter Health, Ambetter Health of Delaware.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

William Christian Ahrenholz Pa 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 ID4082083027
PECOS Enrollment IDI20221213002398
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.

Hospital Affiliations CMS Care Compare

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

Mt Sinai Hospital Medical Center

Acute Care Hospitals · Chicago, IL
1/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number140018
Location1500 S Fairfield AveChicago, IL 60608 · Cook County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 60611 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
$94.06 typical visit price
range $60.08 – $183.39
Typical copayment $23.51 (range $15.02 – $45.84)
Most-billed visit code 99203
Established Patient
$74.80 typical visit price
range $18.97 – $148.12
Typical copayment $18.70 (range $4.74 – $37.03)
Most-billed visit code 99213
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 11

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

KIERSTEN JUDITH O'NEILL PA-C
Physician Assistant
676 N SAINT CLAIR ST STE 2100
CHICAGO, IL 60611
Cook County (312) 695-1800
GREGORY ROBERT COOK JR. APRN, CNP
Nurse Practitioner
676 N SAINT CLAIR ST STE 2100
CHICAGO, IL 60611
Cook County (312) 695-1800
DR. MAANASI SAMANT MD
Internal Medicine (Pulmonary Disease)
676 N SAINT CLAIR ST STE 2100
CHICAGO, IL 60611
Cook County (312) 695-1800
DR. JAMES M WALTER MD
Internal Medicine (Pulmonary Disease)
676 N SAINT CLAIR ST STE 2100
CHICAGO, IL 60611
Cook County (312) 695-1800
FAITH LLOYD APRN, CNP
Nurse Practitioner
676 N SAINT CLAIR ST STE 2100
CHICAGO, IL 60611
Cook County (312) 695-1800
MELISSA HUML APRN, CNP
Nurse Practitioner
676 N SAINT CLAIR ST STE 2100
CHICAGO, IL 60611
Cook County (312) 695-1800
PIOTR BABINSKI M.D.
Internal Medicine (Pulmonary Disease)
676 N SAINT CLAIR ST STE 2100
CHICAGO, IL 60611
Cook County (312) 695-1800
BRIAN T GARIBALDI M.D.
Internal Medicine (Pulmonary Disease)
676 N SAINT CLAIR ST STE 2100
CHICAGO, IL 60611
Cook County (312) 695-1800

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 Ahrenholz's NPI number?

The NPI number for William Ahrenholz is 1043968001. It was assigned to this individual provider in the NPPES registry on March 17, 2022.

Where is William Ahrenholz located?

William Ahrenholz practices at 676 N Saint Clair St Ste 2100, Chicago, IL 60611. The listed phone number is (312) 695-1800.

What is William Ahrenholz's specialty?

The primary specialty registered for this NPI is Physician Assistant with taxonomy code 363A00000X.

Is William Ahrenholz enrolled in Medicare?

Yes. William Ahrenholz 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.

What insurance does William Ahrenholz accept?

Health plans from Ambetter Health, Ambetter Health of Delaware and Ambetter from Home State Health list William Ahrenholz 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 Ahrenholz affiliated with any hospitals?

According to CMS data, William Ahrenholz is affiliated with Mt Sinai Hospital Medical Center.

When was this NPI record last updated?

The NPPES record for William Ahrenholz was last updated on July 10, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 30 days 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.