Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Cy Stein, MD

Medical Oncology Physician in Duarte, CA · enumerated 2006.

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

National Provider Identifier

1871673350

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name Cy Stein

Credential MD

Sex Male

Practice address 1500 Duarte Rd, City of Hope - Medical Oncology Bldg 51, Duarte, CA, 91010

Phone (626) 471-3890

Fax (626) 471-7322

Enumeration date Oct 17, 2006

Last updated in NPPES Nov 13, 2020

Taxonomy & licenses

207RX0202X Medical Oncology Physician Allopathic & Osteopathic Physicians · License 157794 (NY) Secondary

207RX0202X Medical Oncology Physician Allopathic & Osteopathic Physicians · License G89157 (CA) Primary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

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 specialty is Cy Stein?

Cy Stein is registered in NPPES with the primary taxonomy of Medical Oncology Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

Is this the official NPI registry?

No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2020-11-13.