Doctor profile · Federal record

Dr. Mark Yun, MD

Rheumatology Physician (CMS: Rheumatology) · Sturbridge, MA

  • NPI 1326538687
  • Accepts Medicare
  • 14 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
198 Charlton RD
Sturbridge, MA 015661571
(508) 765-7878
Mailing address
Po Box 415348
Boston, MA 022415348

Credentials & registration

NPPES · NUCC
NPI registered
May 2018 — 8 yrs on file
Profile last updated
October 3, 2023
Year of graduation
2012 — 14 yrs since
Specialty taxonomy
207RR0500X — NUCC code
State license (1)
Massachusetts #1015976

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1326538687. Last verified May 11, 2026.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$19
Transactions
1
Manufacturers
1
Payer (manufacturer) Industry Txns Amount
Amgen INC. 1 $19.33

By nature of payment

Food and Beverage
$19

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
75
Patients
11
Total drug cost
$64,237
Drug Type Claims Patients Total cost
Prednisone Generic 23 11 $337
Hydroxychloroquine Sulfate Generic 14 0 $2,127
Risedronate Sodium Dr (Risedronate Sodium) Brand 14 0 $1,906
Methotrexate (Methotrexate Sodium) Brand 12 0 $352
Otezla (Apremilast) Brand 12 0 $59,515

Frequently asked questions

Auto-generated from federal data
What is Dr. Mark Yun's medical specialty?
Dr. Mark Yun practices Rheumatology Physician in Sturbridge, MA.
Where does Dr. Mark Yun practice?
Dr. Mark Yun practices at 198 Charlton RD, Sturbridge, MA 015661571. Office phone: 5087657878.
What is Dr. Mark Yun's NPI?
Dr. Mark Yun's National Provider Identifier (NPI) is 1326538687, issued by NPPES.
Does Dr. Mark Yun accept Medicare assignment?
Yes. Dr. Mark Yun accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.