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

Dr. Dheeraj Mahajan, M.D.

Internal Medicine Physician in Oak Park, IL · enumerated 2006.

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

National Provider Identifier

1831133693

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Registry record

Entity type Individual (Type 1)

Name Dr. Dheeraj Mahajan

Credential M.D.

Sex Male

Practice address Oak Park, IL, 60302

Phone (708) 486-2700

Fax (708) 486-2700

Enumeration date Jun 15, 2006

Last updated in NPPES Mar 17, 2026

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 036106392 (IL) Primary

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 036-106392 (IL) Secondary

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
036106392	Medicaid	IL	-

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 Dheeraj Mahajan practice?

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

What is the NPI number for Dheeraj Mahajan?

The National Provider Identifier (NPI) for Dheeraj Mahajan is 1831133693, a Type 1 (individual) record in the CMS NPPES registry.

Other providers at this practice address

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2026-03-17.