NPI Portal NPI Lookup & Verification

Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Mark A Diehl, MD

Family Medicine Physician in Oklahoma City, OK · enumerated 2006.

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

National Provider Identifier

1467410357

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)
Name Mark A Diehl
Credential MD
Sex Male
Practice address 4221 S Western Ave, Suite 3030, Oklahoma City, OK, 73109
Phone (405) 636-7650
Fax (405) 636-7743
Enumeration date May 2, 2006
Last updated in NPPES Jul 19, 2017

Taxonomy & licenses

207Q00000X Family Medicine Physician Allopathic & Osteopathic Physicians · License 12883 (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
200059480A 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 Mark Diehl practice?
The practice location on file with NPPES is in Oklahoma City, OK. Providers can have multiple locations; NPPES lists the primary practice address.
What is the NPI number for Mark Diehl?
The National Provider Identifier (NPI) for Mark Diehl is 1467410357, a Type 1 (individual) record in the CMS NPPES registry.

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2017-07-19.