Ryan C. Chang, MD

NPI 1831277417ActiveIndividual· Internal Medicine, Critical Care Medicine· San Francisco, CA

Internal Medicine, Critical Care Medicine (MD) in San Francisco, California, trained at George Washington University School of Medicine (class of 1996). Part D covered 190 prescriptions written in 2024, 53% of them generic. Abbvie Inc. reported $86.99 in payments in 2025, mostly food and beverage.

Overview

NPI	1831277417
Status	Active
Entity type	Individual
Credential	MD
Sole proprietor	No
NPI issued	Nov 1, 2006
Last updated in NPPES	Sep 1, 2026
Certified by provider	Sep 1, 2026

Specialties and licenses

Taxonomy	Code	License	State
Internal Medicine, Critical Care Medicine Primary	207RC0200X	A63692	CA

About license numbers in NPPES

Exclusion screening

List	Result	Details
HHS-OIG LEIE · Oct 9, 2026	No match	Checked by NPI and by name + state
North Carolina Medicaid · Nov 10, 2026	No match	—
New York OMIG · Nov 10, 2026	No match	—
Ohio Medicaid · Nov 10, 2026	No match	—
Pennsylvania Medicheck · Nov 10, 2026	No match	—
Washington HCA · Nov 10, 2026	No match	—

Official OIG search · How matching works ·Bulk check a roster

Medicare

Enrollment (PECOS)	Enrolled Practitioner - Critical Care (Intensivists) (CA)

Part D prescriptions in 2024

Prescriptions (claims)	190 · 318 30-day fills
Patients	57
Total drug cost	$41,364
Generic share	53% of claims

Medicare sources and data years

Education and affiliations

Medical school	George Washington University School of Medicine
Graduation year	1996
Medicare specialty	Critical Care (Intensivists)
Secondary specialties	Internal Medicine, Pulmonary Disease