1. Home
  2. Directory
  3. Arizona
  4. Phoenix
  5. Transplant Surgery
  6. NPI Profile
Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

WILLEM J VAN DER WERF M.D.
NPI 1275563397
Transplant Surgery in Phoenix, AZ

Active since July 04, 2006PECOS EnrolledAccepts Medicare Assignment
2218 N 3RD ST, PHOENIX, AZ 85004(602) 252-2543(602) 252-3861 Get Directions Write a Review

NPPES record last updated: September 2, 2026. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Sep 2, 2026, Nov 12, 2024, Oct 8, 2020 (3 updates tracked since 2020).

About Willem J Van Der Werf M.d. NPPES

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

WILLEM J VAN DER WERF M.D. (NPI 1275563397) is an individual transplant surgery provider in Phoenix, Arizona, licensed in Arizona (49927) and active in the NPI registry since July 2006. He is enrolled in Medicare PECOS, maintains a secondary practice location in Phoenix, and is a graduate of University Of California, San Francisco School Of Medicine (1988).

NPPES Registry Identity

NPI1275563397
Entity TypeIndividualMale
Primary Taxonomy204F00000X
Provider Legal NameWILLEM J VAN DER WERFCredential: M.D.
Location Address2218 N 3RD STPhoenix, AZ 85004-1401
Mailing Address2218 N 3rd StPhoenix, AZ 85004-1401 · (602) 252-2543 · Fax (602) 252-3861
Phone(602) 252-2543
Fax(602) 252-3861
Sole ProprietorNo
Medical School CMSUniversity Of California, San Francisco School Of MedicineGraduated 1988
Enumeration DateJuly 4, 2006
Last NPPES UpdateSeptember 2, 20263 updates tracked since enumeration
NPPES CertifiedSeptember 2, 2026
✔ NPI 1275563397 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyTransplant SurgeryAllopathic & Osteopathic Physicians
Taxonomy Code204F00000X
License✔ Licensed in AZ · 49927
Definition
A surgeon who specializes in transplant surgery. Source: National Uniform Claim Committee
Also ListedSpecialistTaxonomy 174400000X · License 5249271205 (UT)
2218 N 3RD ST, Phoenix, AZ 85004
Open in Google Maps ↗

Secondary Practice Location 1

Location 1500 W Thomas Rd Ste 300Phoenix, AZ 85013-4294 · Phone (602) 406-8000 · Fax (602) 406-3111

Other Identifiers 6

Medicaid119626000WY
OtherQM000006442Altius
Other4658850Cigna
Other52492781200001Blue Cross Blue Shield
Medicaid806894300ID
OtherTPRA07781Molina

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Ambetter from Arizona Complete Health, Ambetter Health, Blue Cross Blue Shield of Arizona 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

Willem J Van Der Werf M.d. 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 ID4385636737
PECOS Enrollment IDI20160204001394
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

2

Medicare enrollment records show Willem Van Der Werf reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Arizona Transplant Associates, PC
Same address
Transplant Surgery
2218 N 3RD ST
Phoenix, AZ 85004
  • Reassigned Medicare billing, Arizona enrollment
  • 5 clinicians in this Medicare group
NPI 1447344908 (602) 252-2543
St. Joseph's Hospital And Medical Center
0.8 mi
Emergency Care
350 W THOMAS RD
Phoenix, AZ 85013
  • Reassigned Medicare billing, Arizona enrollment
  • 126 clinicians in this Medicare group
NPI 1255382412 (602) 406-3000

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

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.

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.
41 services23 patients

Other Providers at the Same Location NPPES 6

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

LAWRENCE JAMES KOEP M.D.
Transplant Surgery
2218 N 3RD ST
PHOENIX, AZ 85004
Maricopa County (602) 252-2543
JEFFREY ALAN BRINK M.D.
Transplant Surgery
2218 N 3RD ST
PHOENIX, AZ 85004
Maricopa County (602) 252-2543
ARIZONA TRANSPLANT ASSOCIATES, PC
Transplant Surgery
2218 N 3RD ST
PHOENIX, AZ 85004
Maricopa County (602) 252-2543
DR. THOMAS CHALY JR. M.D.
Transplant Surgery
2218 N 3RD ST
PHOENIX, AZ 85004
Maricopa County (602) 252-2543
JAMES LOFTON CASHMAN M.D.
Transplant Surgery
2218 N 3RD ST
PHOENIX, AZ 85004
Maricopa County (602) 252-2543
CHRISTOPHER STAHL M.D.
Transplant Surgery
2218 N 3RD ST
PHOENIX, AZ 85004
Maricopa County (602) 252-2543

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 Willem Van Der Werf's NPI number?

The NPI number for Willem Van Der Werf is 1275563397. It was assigned to this individual provider in the NPPES registry on July 4, 2006.

Where is Willem Van Der Werf located?

Willem Van Der Werf practices at 2218 N 3rd St, Phoenix, AZ 85004. The listed phone number is (602) 252-2543.

What is Willem Van Der Werf's specialty?

The primary specialty registered for this NPI is Transplant Surgery with taxonomy code 204F00000X.

Is Willem Van Der Werf enrolled in Medicare?

Yes. Willem Van Der Werf 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 Willem Van Der Werf's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Willem Van Der Werf reassigns Medicare benefits to 2 organizations: Arizona Transplant Associates, PC (Phoenix, AZ) and St. Joseph's Hospital And Medical Center (Phoenix, AZ). 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 Willem Van Der Werf's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Willem Van Der Werf accept?

Health plans from Ambetter Health, Ambetter from Arizona Complete Health, Blue Cross Blue Shield of Arizona and Imperial Insurance Companies, Inc. list Willem Van Der Werf 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.

When was this NPI record last updated?

The NPPES record for Willem Van Der Werf was last updated on September 2, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 51 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.