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WILLIAM THOMAS HALSEY MD
NPI 1295775237
Anesthesiology in San Francisco, CA

Active since June 07, 2006PECOS Enrolled
3700 CALIFORNIA ST, SAN FRANCISCO, CA 94118(415) 719-0000 Get Directions Write a Review

NPPES record last updated: July 11, 2007. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About William Thomas Halsey Md NPPES

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

WILLIAM THOMAS HALSEY MD (NPI 1295775237) is an individual anesthesiology provider in San Francisco, California, licensed in California (C37471) and active in the NPI registry since June 2006. He is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1295775237
Entity TypeIndividualMale
Primary Taxonomy207L00000X
Provider Legal NameWILLIAM THOMAS HALSEYCredential: MD
Location Address3700 CALIFORNIA STSan Francisco, CA 94118-1618
Mailing AddressPo Box 39000, Dept 33995San Francisco, CA 94139-0001 · (503) 372-2740 · Fax (503) 372-2754
Phone(415) 719-0000
Sole ProprietorNo
Enumeration DateJune 7, 2006
Last NPPES UpdateJuly 11, 2007
✔ NPI 1295775237 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyAnesthesiologyAllopathic & Osteopathic Physicians
Taxonomy Code207L00000X
License✔ Licensed in CA · C37471
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 ListedAnesthesiology · Pain MedicineTaxonomy 207LP2900X · License C37471 (CA)
3700 CALIFORNIA ST, San Francisco, CA 94118
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Other Identifiers 3

Medicaid00C374710CA
Medicare UPINA36637
Medicare ID-Type Unspecified00C374710CA

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

William Thomas Halsey Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

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 Reassignment

Medicare enrollment records show William Halsey reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Brookwood Anesthesia Inc
47 mi
Anesthesiology
76 BROOKWOOD AVE STE B
Santa Rosa, CA 95404
  • Reassigned Medicare billing, California enrollment
NPI 1225811623 (707) 523-4907

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 3

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 lower spine 00630
Anesthesia for a lower spine procedure involves administering medication to block pain and sensation in your back. This ensures comfort and stillness during the procedure. The type of anesthesia used depends on the specific procedure and your overall health.
56 services45 patients
Anesthesia for other procedure on upper spine 00600
Anesthesia for upper spine procedures is a method to numb sensation in your back. It's often done via injection or through a catheter to deliver medication that blocks nerves. This ensures comfort and prevents pain during your spine procedure.
29 services23 patients
Anesthesia for closed procedure on pubic bone or pelvic joint 01160
Anesthesia for a closed procedure on the pubic bone or pelvic joint involves using medication to block pain during the procedure. This can be either general anesthesia, where you're unconscious, or regional anesthesia, where only a specific area of your body is numbed. It ensures a comfortable, pain-free experience during the procedure.
20 services17 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.

DAVID HOWARD IRWIN MD
Anesthesiology
3700 CALIFORNIA ST
SAN FRANCISCO, CA 94118
San Francisco County (415) 719-0000
STEVEN GARY VITCOV MD
Anesthesiology
3700 CALIFORNIA ST
SAN FRANCISCO, CA 94118
San Francisco County (415) 719-0000
SAM SHENG SHAY MD
Anesthesiology
3700 CALIFORNIA ST
SAN FRANCISCO, CA 94118
San Francisco County (415) 719-0000
JOHN C. MORETTO MD
Pathology (Clinical Pathology/Laboratory Medicine)
3700 CALIFORNIA ST
SAN FRANCISCO, CA 94118
San Francisco County (415) 600-2200
CARRIE HAVERTY MS, CGC
Genetic Counselor, MS
3700 CALIFORNIA ST, CALIFORNIA PACIFIC MEDICAL CENTER, G330
SAN FRANCISCO, CA 94118
San Francisco County (415) 600-2601
RICHARD GARCIA-KENNEDY MD
Pathology (Clinical Pathology/Laboratory Medicine)
3700 CALIFORNIA ST
SAN FRANCISCO, CA 94118
San Francisco County (415) 600-2200
ZANETA CHA
Genetic Counselor, MS
3700 CALIFORNIA ST
SAN FRANCISCO, CA 94118
San Francisco County (415) 600-6400
MRS. KENDALL PLAMANN GLYNN MS, CGC
Genetic Counselor, MS
3700 CALIFORNIA ST, G330
SAN FRANCISCO, CA 94118
San Francisco County (415) 600-2681

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 Halsey's NPI number?

The NPI number for William Halsey is 1295775237. It was assigned to this individual provider in the NPPES registry on June 7, 2006.

Where is William Halsey located?

William Halsey practices at 3700 California St, San Francisco, CA 94118. The listed phone number is (415) 719-0000.

What is William Halsey's specialty?

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

Is William Halsey enrolled in Medicare?

Yes. William Halsey is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for William Halsey's services?

According to the CMS Revalidation Reassignment List (October 2026 release), William Halsey reassigns Medicare benefits to Brookwood Anesthesia Inc (Santa Rosa, CA). The 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 Halsey's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for William Halsey was last updated on July 11, 2007. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 19 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.