Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Mark Allen Schaeffer, M.D.

Internal Medicine Physician in Princeton, NJ · enumerated 2007.

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

National Provider Identifier

1194866087

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name Mark Allen Schaeffer

Credential M.D.

Sex Male

Practice address 800 Bunn Dr, Suite 302, Princeton, NJ, 08540

Phone (609) 921-1680

Fax (609) 921-1438

Enumeration date Feb 12, 2007

Last updated in NPPES Mar 11, 2012

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 25MA04680500 (NJ) 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
271656004	Other	NJ	TAX ID # PRINCETON PREMIER MEDICINE, LLC

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 Schaeffer practice?

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

What is the NPI number for Mark Schaeffer?

The National Provider Identifier (NPI) for Mark Schaeffer is 1194866087, 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 2012-03-11.