Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Karen Debra Leitner, M.D.

Internal Medicine Physician in Cambridge, MA · enumerated 2006 · practices at Cambridge Health Alliance.

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

National Provider Identifier

1043283658

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Registry record

Entity type Individual (Type 1)

Name Dr. Karen Debra Leitner

Credential M.D.

Sex Female

Practice address 237 Hampshire St, Cambridge, MA, 02139

Phone (617) 575-5570

Enumeration date Feb 13, 2006

Last updated in NPPES Nov 29, 2011

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 228045 (MA) Primary

208000000X Pediatrics Physician Allopathic & Osteopathic Physicians · License 228045 (MA) 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
2120763	Medicaid	MA	-

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

How do I verify Karen Leitner's NPI record?

Cross-check NPI 1043283658 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Is NPI 1043283658 active?

Yes, as of the latest NPPES snapshot, NPI 1043283658 is active (record last updated 2011-11-29).

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2011-11-29.