William George Tan, MD

NPI 1386754455ActiveIndividual· Internal Medicine· Eldersburg, MD

Internal Medicine (MD) in Eldersburg, Maryland, trained at University of Maryland School of Medicine (class of 1984). Their prescriptions cost Medicare Part D more than their services did: $705,987 for 6,257 claims, against $90,362 paid for services in 2024. Amgen Inc. was the largest of 3 companies reporting payments in 2025, $108.18 in all, mostly food and beverage.

Overview

NPI	1386754455
Status	Active
Entity type	Individual
Credential	MD
Sole proprietor	No
NPI issued	Aug 30, 2006
Last updated in NPPES	Jul 8, 2007

Specialties and licenses

Taxonomy	Code	License	State
Internal Medicine Primary	207R00000X	D34849	MD

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 4, 2026	No match	—
New York OMIG · Nov 4, 2026	No match	—
Ohio Medicaid · Nov 4, 2026	No match	—
Pennsylvania Medicheck · Nov 4, 2026	No match	—
Washington HCA · Nov 4, 2026	No match	—

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

Medicare

Enrollment (PECOS)	Enrolled Practitioner - Internal Medicine (MD)
Accepts assignment	Yes (participating)

Medicare services in 2024

Medicare patients	346
Services billed	1,820 across 42 procedure codes
Paid by Medicare	$90,362

Part D prescriptions in 2024

Prescriptions (claims)	6,257 · 14,703 30-day fills
Patients	410
Total drug cost	$705,987
Generic share	86% of claims

Medicare sources and data years

Education and affiliations

Medical school	University of Maryland School of Medicine
Graduation year	1984
Medicare specialty	Internal Medicine
Secondary specialties	Geriatric Medicine
Telehealth	Offers telehealth