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WILLIAM RYAN FOSTER MD
NPI 1093204174
Anesthesiology in Tucson, AZ

Active since May 04, 2018PECOS EnrolledAccepts Medicare Assignment
5301 E GRANT RD, TUCSON, AZ 85712(520) 324-2030 Get Directions Write a Review

NPPES record last updated: October 3, 2025. Verified against the NPPES registry weekly; last sync: November 01, 2026.

Record update history: Jul 22, 2022, Jun 12, 2019, May 4, 2018 (3 updates tracked since 2018).

About William Ryan Foster Md NPPES

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

WILLIAM RYAN FOSTER MD (NPI 1093204174) is an individual anesthesiology provider in Tucson, Arizona, licensed in California (165371) and active in the NPI registry since May 2018. He is enrolled in Medicare PECOS and is a graduate of New York Medical College (2018).

NPPES Registry Identity

NPI1093204174
Entity TypeIndividualMale
Primary Taxonomy207L00000X
Provider Legal NameWILLIAM RYAN FOSTERCredential: MD
Location Address5301 E GRANT RDTucson, AZ 85712-2874
Mailing Address3510 N Craycroft Rd Apt 6203Tucson, AZ 85718-7287 · (425) 829-8895
Phone(520) 324-2030
Sole ProprietorYes
Medical School CMSNew York Medical CollegeGraduated 2018
Enumeration DateMay 4, 2018
Last NPPES UpdateOctober 3, 20253 updates tracked since enumeration
NPPES CertifiedOctober 3, 2025
✔ NPI 1093204174 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyAnesthesiologyAllopathic & Osteopathic Physicians
Taxonomy Code207L00000X
Licenses✔ Licensed in CA · 165371✔ Licensed in AZ · 65774
Definition
An anesthesiologist is trained to provide pain relief and maintenance, or restoration, of a stable condition during and immediately following an operation or an obstetric or diagnostic procedure. The anesthesiologist assesses the risk of the patient undergoing surgery and optimizes the patient's condition prior to, during and after surgery. In addition to these management responsibilities, the anesthesiologist provides medical management and consultation in pain management and critical care medicine. Anesthesiologists diagnose and treat acute, long-standing and cancer pain problems; diagnose and treat patients with critical illnesses or severe injuries; direct resuscitation in the care of patients with cardiac or respiratory emergencies, including the need for artificial ventilation; and supervise post-anesthesia recovery.
Also ListedInternal MedicineTaxonomy 207R00000X · License R76655 (AZ)
5301 E GRANT RD, Tucson, AZ 85712
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Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Blue Cross Blue Shield of Arizona, Oscar Health Plan, Inc..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 Ryan Foster 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 ID7416207451
PECOS Enrollment IDI20220913003988
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 William Foster reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Ias Arizona PLLC
Same address
Anesthesiology
5301 E GRANT RD
Tucson, AZ 85712
  • Reassigned Medicare billing, Arizona enrollment
  • 264 clinicians in this Medicare group
NPI 1689359747 (520) 327-5461
Northwest Hbp Medical Services LLC
9.0 mi
Emergency Medicine
6200 N LA CHOLLA BLVD
Tucson, AZ 85741
  • Reassigned Medicare billing, Arizona enrollment
  • 664 clinicians in this Medicare group
NPI 1407353006 (520) 229-2657

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 5

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.

Anesthesia for other procedure on esophagus, stomach, or upper small bowel using an endoscope 00731
This procedure involves the use of an endoscope, a flexible tube with a light and camera, to examine your esophagus, stomach, or upper small bowel. Anesthesia ensures you are comfortable and pain-free during the procedure.
27 services27 patients
Anesthesia for other procedure on large bowel using an endoscope 00811
Anesthesia for an endoscopic procedure on the large bowel ensures comfort and relaxation during the procedure. You'll be given medication to make you drowsy or asleep, eliminating any discomfort. The medication can be administered through a vein or inhaled.
18 services18 patients
Injection of anesthetic agent and/or steroid into thigh nerve (femoral nerve) 64447
This procedure involves injecting a numbing agent and/or steroid into a nerve in your thigh. It's done to alleviate pain or inflammation. A needle will be carefully positioned near the nerve, and the medicine will be administered.
16 services16 patients
Anesthesia for exam of colon using an endoscope 00812
Anesthesia for a colon examination with an endoscope is a method used to ensure comfort during the procedure. It involves administering medication to help you relax or sleep, thus reducing discomfort as the endoscope, a thin, flexible tube, is navigated through your colon.
12 services12 patients
Injection of anesthetic agent and/or steroid into arm nerve bundle (brachial plexus) 64415
This procedure involves injecting a numbing agent or steroid into your arm's nerve bundle. It's done to manage pain or inflammation. The injection helps block nerve signals that cause discomfort, providing relief. It's a safe, common procedure.
11 services11 patients

Other Providers at the Same Location NPPES 20

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

HOLLY JEANNE GRAHAM M.D.
Anesthesiology
5301 E GRANT RD, THMEP
TUCSON, AZ 85712
Pima County (520) 324-5095
SAMANTHA PENN PHARMD
Pharmacist
5301 E GRANT RD
TUCSON, AZ 85712
Pima County (520) 324-5122
DR. VICTOR HUGO RUIZ PHARMD
Student in an Organized Health Care Education/Training Program
5301 E GRANT RD
TUCSON, AZ 85712
Pima County (520) 324-2516
SARA PETTEY SANDIFER MD
Student in an Organized Health Care Education/Training Program
5301 E GRANT RD
TUCSON, AZ 85712
Pima County (520) 324-5095
JOSHUA LEE M.D.
Internal Medicine
5301 E GRANT RD
TUCSON, AZ 85712
Pima County (520) 324-5524
VANESSA LYNN PORTOR RN
Registered Nurse (Lactation Consultant)
5301 E GRANT RD
TUCSON, AZ 85712
Pima County (520) 324-5730
MRS. KRISTY BELONE FNP-C
Nurse Practitioner (Family)
5301 E GRANT RD
TUCSON, AZ 85712
Pima County (520) 324-5461
LORRAINE Y YENTZER AGACNP
Nurse Practitioner (Gerontology)
5301 E GRANT RD
TUCSON, AZ 85712
Pima County (520) 327-5461

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 Foster's NPI number?

The NPI number for William Foster is 1093204174. It was assigned to this individual provider in the NPPES registry on May 4, 2018.

Where is William Foster located?

William Foster practices at 5301 E Grant Rd, Tucson, AZ 85712. The listed phone number is (520) 324-2030.

What is William Foster's specialty?

The primary specialty registered for this NPI is Anesthesiology with taxonomy code 207L00000X.

Is William Foster enrolled in Medicare?

Yes. William Foster 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 Foster's services?

According to the CMS Revalidation Reassignment List (October 2026 release), William Foster reassigns Medicare benefits to 2 organizations: Ias Arizona PLLC (Tucson, AZ) and Northwest Hbp Medical Services LLC (Tucson, 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 William Foster's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does William Foster accept?

Health plans from Blue Cross Blue Shield of Arizona and Oscar Health Plan, Inc. list William Foster 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 William Foster was last updated on October 3, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 13 months 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.