Doctor profile · Federal record

Dr. Aaron Greenspan, MD

Gastroenterology Physician (CMS: Gastroenterology) · Saint Louis, MO

  • NPI 1558382911
  • Accepts Medicare
  • 35 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
1 Barnes Jewish Hospital Plz, Div Im Gastroenterology
Saint Louis, MO 631101003
(314) 747-2066
fax (314) 362-2357
Mailing address
Po Box 7412011
Chicago, IL 606742011

Credentials & registration

NPPES · NUCC
NPI registered
July 2006 — 20 yrs on file
Profile last updated
April 17, 2025
Year of graduation
1991 — 35 yrs since
Specialty taxonomy
207RG0100X — NUCC code
State license (1)
Missouri #104978
Medicaid
MO #209140003

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1558382911. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
517
Distinct HCPCS
10
Medicare allowed
$60,758
HCPCS Description Services Patients Avg allowed
99213 Established patient office or other outpatient visit, 20-29 minutes 115 86 $89
45378 Diagnostic exam of large bowel using a flexible endoscope 66 66 $183
43235 Diagnostic exam of esophagus, stomach, and/or upper small bowel using a flexible endoscope 47 46 $95
45380 Biopsy of large bowel using a flexible endoscope 44 44 $173
99231 Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes 38 27 $51
99232 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 36 25 $79
45385 Removal of polyps or growths of large bowel using an endoscope with mechanical snare 31 31 $256
99214 Established patient office or other outpatient visit, 30-39 minutes 31 30 $120
99222 Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 28 27 $131
43239 Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 19 19 $91

In context: peer comparison

Among 42 peers in Saint Louis Gastroenterology Physician, average services per provider: 60. This provider delivers 8.6× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$643
Transactions
14
Manufacturers
5
Payer (manufacturer) Industry Txns Amount
Janssen Biotech, INC. 9 $544.52
Abbvie INC. 2 $38.45
Lilly USA, LLC 1 $23.13
Celgene Corporation 1 $20.93
Ironwood Pharmaceuticals, INC 1 $16.35

By nature of payment

Food and Beverage
$643

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
1,343
Patients
316
Total drug cost
$157,085
Drug Type Claims Patients Total cost
Omeprazole Generic 389 111 $6,814
Pantoprazole Sodium Generic 224 66 $4,173
Linzess (Linaclotide) Brand 118 26 $76,752
Famotidine Generic 111 28 $2,130
Amitriptyline Hcl Generic 96 25 $2,028
Dicyclomine Hcl Generic 76 24 $2,500
Metoclopramide Hcl Generic 64 20 $1,003
Cholestyramine (Cholestyramine (With Sugar)) Brand 49 0 $5,628
Azathioprine Generic 43 0 $2,247
Sucralfate Generic 42 16 $1,969

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Aaron Greenspan's medical specialty?
Dr. Aaron Greenspan practices Gastroenterology Physician in Saint Louis, MO.
Where does Dr. Aaron Greenspan practice?
Dr. Aaron Greenspan practices at 1 Barnes Jewish Hospital Plz, Saint Louis, MO 631101003. Office phone: 3147472066.
What is Dr. Aaron Greenspan's NPI?
Dr. Aaron Greenspan's National Provider Identifier (NPI) is 1558382911, issued by NPPES.
Does Dr. Aaron Greenspan accept Medicare assignment?
Yes. Dr. Aaron Greenspan accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Aaron Greenspan commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99213); Diagnostic exam of large bowel using a flexible endoscope (HCPCS 45378); Diagnostic exam of esophagus, stomach, and/or upper small bowel using a flexible endoscope (HCPCS 43235). Source: CMS Medicare Physician & Other Practitioners file.