WILLIAM THOMAS HALSEY (MD) – Anesthesiology Physician, NPI 1295775237

WILLIAM THOMAS HALSEY (MD) is a healthcare provider. based in San francisco, California. specializing in Anesthesiology Physician. They hold the professional credentials MD. They hold a License No. C37471 (CA). The NPI Number for WILLIAM THOMAS HALSEY (MD) is 1295775237

Main info

Male
52 Years Of Experience
Accepts Medicare Assignment
Name
WILLIAM THOMAS HALSEY (MD)
NPI
1295775237
Phone
(503) 372-2740
Address
PO BOX 39000
Enumeration Date
7 June 2006
Last Update Date
11 July 2007

Doctor Profile

Medical School Name
UNIVERSITY OF TEXAS MEDICAL BRANCH AT GALVESTON
Secondary Phone
4156003293
Graduation Year
1974 (52 years ago)
PAC ID
6305905704
Group Practice PAC ID
2163410770
Professional Enrollment ID
I20081029000881
Data current as of
19 May 2026

Profile Insights

NPPES metrics only — not quality of care.

Methodology
Experience59
Completeness75
Years active:20State licenses:1Digital endpointsOther names

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Provider Addresses for WILLIAM THOMAS HALSEY (MD)

  • PO BOX 39000

    DEPT 33995

    SAN FRANCISCO, CA 941390001

    Phone: (503) 372-2740

    Fax: (503) 372-2754

    Type: Mailing

  • 3700, California Street, Jordan Park, San Francisco, California, 94118, United States

    SAN FRANCISCO, CA 941181618

    Phone: (415) 719-0000

    Type: Location

NPPES updates history

No NPPES updates recorded for this provider.

Prescription Activity

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Open Payments (CMS)

No Open Payments data available for this provider.

This can happen when there are no reportable CMS Open Payments records.

Medicare Enrollment & Revalidation

Source: CMS public data · Not endorsed by CMS ·

Educational use only—not medical, billing, or legal advice.

PECOS enrollment status

Participating (accepts Medicare assignment)

Enrollment effective: 2008-10-29

PECOS data refreshed: 2026-05-27

Medicare revalidation (CMS due date list)

Due date not assigned yet

CMS is tracking this Medicare enrollment for revalidation, but has not published a due date.

Enrollment records

1

Earliest due date

Not assigned (TBD)

CMS data updated

2026-06-01

Revalidation progress

  1. Medicare enrolled
  2. On CMS revalidation list
  3. Due date assigned
  4. Revalidate in PECOS

CMS enrollment records

Enrollment IDTypeSpecialtyStateDue date
I20081029000881IAnesthesiologyCATBD

What to do next

  • No action required while the due date shows TBD.
  • Check the CMS Revalidation Lookup Tool periodically — CMS updates the list about every 60 days.
  • Do not submit a revalidation application in PECOS until CMS publishes a concrete due date.

Verify on CMS Revalidation Lookup Tool

Prepare CMS-855 application → · Look up this NPI in PECOS → · Verify on CMS PECOS

Medicare Utilization (FFS)

Source: CMS public data · Not endorsed by CMS · Beneficiary counts under 11 are suppressed in source data ·

Educational use only—not medical, billing, or legal advice.

No Medicare fee-for-service utilization data available for this provider in our database.

Insurance plans in this area (ZIP 94139)

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Group practice members

Group practice members are other physicians who share the same Group Practice PAC ID with this doctor. When doctors form a group practice and register in PECOS as a single entity, they receive a shared identification number. This table lists all providers in the same group practice.
PAC ID: 2163410770View full group profile

Reviews

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Frequently asked questions

Where can patients find WILLIAM THOMAS HALSEY (MD)'s NPI?
You can confirm WILLIAM THOMAS HALSEY (MD) with NPI 1295775237; it appears in the national provider directory.
Is WILLIAM THOMAS HALSEY (MD) active in the national directory?
WILLIAM THOMAS HALSEY (MD)'s public NPI profile is in an active state.
What field does WILLIAM THOMAS HALSEY (MD) work in?
You can think of WILLIAM THOMAS HALSEY (MD) as practicing within Anesthesiology Physician. Clinical services aligned with this taxonomy classification.
Where does public data place WILLIAM THOMAS HALSEY (MD)?
The snapshot lists San Francisco, California for WILLIAM THOMAS HALSEY (MD); download NPPES for the complete set.
Does Medicare enrollment show here?
Medicare enrollment screens are separate from the basic NPI extract shown here.

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