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

Dr. Allen J Hamaker, MD

Internal Medicine Physician in Okc, OK · enumerated 2006.

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

National Provider Identifier

1326028663

Verified

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Registry record

Entity type Individual (Type 1)

Name Dr. Allen J Hamaker

Credential MD

Sex Male

Practice address Okc, OK, 73112

Phone (405) 949-6481

Fax (405) 795-5908

Enumeration date Jan 20, 2006

Last updated in NPPES Oct 14, 2014

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

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 20735 (OK) 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
100060090A	Medicaid	OK	-

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

Where does Allen Hamaker practice?

The practice location on file with NPPES is in Okc, OK. Providers can have multiple locations; NPPES lists the primary practice address.

What is the NPI number for Allen Hamaker?

The National Provider Identifier (NPI) for Allen Hamaker is 1326028663, a Type 1 (individual) record in the CMS NPPES registry.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2014-10-14.