Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. William J Sadlack, M.D.

Orthopaedic Surgery Physician in Bethesda, MD · enumerated 2005.

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

National Provider Identifier

1104819168

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name Dr. William J Sadlack

Credential M.D.

Sex Male

Practice address 6420 Rockledge Dr, Suite 2200, Bethesda, MD, 20817

Phone (301) 530-3220

Fax (301) 530-4120

Enumeration date Aug 25, 2005

Last updated in NPPES May 9, 2013

Taxonomy & licenses

207X00000X Orthopaedic Surgery Physician Allopathic & Osteopathic Physicians · License D0019207 (MD) 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
415096100	Medicaid	MD	-
9954	Other	-	CAREFIRST BCBS PROVIDER #

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

What is the NPI number for William Sadlack?

The National Provider Identifier (NPI) for William Sadlack is 1104819168, a Type 1 (individual) record in the CMS NPPES registry.

Where does William Sadlack practice?

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

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2013-05-09.