Doctor profile · Federal record

Dr. Mara Horwitz, MD

Rheumatology Physician (CMS: Rheumatology) · Pediatric Rheumatology Physician · Student in an Organized Health Care Education/Training Program · Saint Louis, MO

  • NPI 1649613332
  • Accepts Medicare
  • 13 yrs in practice
  • Female
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
1225 S Grand Blvd
Saint Louis, MO 631041016
(314) 977-8833
Mailing address
1402 S Grand Blvd Rm R213A
Saint Louis, MO 631041004

Credentials & registration

NPPES · NUCC
NPI registered
April 2013 — 13 yrs on file
Profile last updated
February 5, 2021
Year of graduation
2013 — 13 yrs since
Specialty taxonomy
207RR0500X — NUCC code
State license (1)
Missouri #2016009340

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1649613332. Last verified May 11, 2026.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$83
Transactions
4
Manufacturers
1
Payer (manufacturer) Industry Txns Amount
Amgen INC. 4 $82.71

By nature of payment

Food and Beverage
$83

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
115
Patients
12
Total drug cost
$2,635
Drug Type Claims Patients Total cost
Prednisone Generic 53 12 $701
Methotrexate (Methotrexate Sodium) Brand 31 0 $1,085
Hydroxychloroquine Sulfate Generic 18 0 $751
Allopurinol Generic 13 0 $98

Frequently asked questions

Auto-generated from federal data
What is Dr. Mara Horwitz's medical specialty?
Dr. Mara Horwitz practices Rheumatology Physician in Saint Louis, MO.
Where does Dr. Mara Horwitz practice?
Dr. Mara Horwitz practices at 1225 S Grand Blvd, Saint Louis, MO 631041016. Office phone: 3149778833.
What is Dr. Mara Horwitz's NPI?
Dr. Mara Horwitz's National Provider Identifier (NPI) is 1649613332, issued by NPPES.
Does Dr. Mara Horwitz accept Medicare assignment?
Yes. Dr. Mara Horwitz accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.