Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum Sole proprietor

Dr. William Allen Rumack, M.D.

Orthopaedic Surgery Physician in West Hills, CA · enumerated 2006.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1740257542

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name Dr. William Allen Rumack

Credential M.D.

Sex Male

Practice address West Hills, CA, 91307

Phone (818) 888-2855

Fax (818) 888-0702

Enumeration date Mar 1, 2006

Last updated in NPPES May 11, 2023

Street address withheld: NPPES sole-proprietor addresses can be home addresses. See our data policy.

Taxonomy & licenses

207X00000X Orthopaedic Surgery Physician Allopathic & Osteopathic Physicians · License K2785 (TX) Secondary

207X00000X Orthopaedic Surgery Physician Allopathic & Osteopathic Physicians · License DR38255 (CO) Secondary

207X00000X Orthopaedic Surgery Physician Allopathic & Osteopathic Physicians · License A79561 (CA) Primary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

Other identifiers

Identifier	Type	State	Issuer
1104410001	Other	CA	MEDICARE DME SUPPLIER #
955118	Other	CA	QME #
DR 38255	Other	CO	MEDICAL BOARD OF COLORADO
A79561	Other	CA	MEDICAL BOARD OF CA
K2785	Other	TX	MEDICAL BOARD OF TEXAS
W8424	Medicaid	CA	-
WA79561B	Other	CA	MEDICARE PERFORMING
953718732	Other	CA	TAX ID #

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.

Read the full guide → Validate an NPI →

Frequently asked questions

What specialty is William Rumack?

William Rumack is registered in NPPES with the primary taxonomy of Orthopaedic Surgery Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

Is this the official NPI registry?

No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2023-05-11.