Doctor profile · Federal record

Dr. Mark Diamond, D.O.

Hospitalist Physician (CMS: Internal Medicine) · Internal Medicine Physician · Joliet, IL

  • NPI 1265402804
  • Accepts Medicare
  • 33 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
2100 Glenwood Ave
Joliet, IL 604355487
(815) 725-2121
fax (815) 744-3117
Mailing address
Po Box 713260
Chicago, IL 606771260

Credentials & registration

NPPES · NUCC
NPI registered
January 2006 — 20 yrs on file
Profile last updated
August 7, 2023
Year of graduation
1993 — 33 yrs since
Specialty taxonomy
208M00000X — NUCC code
State license (1)
Illinois #036091440
Medicaid
IL #036091440

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1265402804. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
1,216
Distinct HCPCS
5
Medicare allowed
$157,621
HCPCS Description Services Patients Avg allowed
99233 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 554 213 $125
99239 Hospital discharge day management, more than 30 minutes 232 206 $120
99223 Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 231 206 $182
99232 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 185 108 $83
99291 Critical care, first 30-74 minutes 14 14 $227

In context: peer comparison

Among 6 peers in this city , average services per provider: 229. This provider delivers 5.3× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$191
Transactions
13
Manufacturers
1
Payer (manufacturer) Industry Txns Amount
Novartis Pharmaceuticals Corporation 13 $190.69

By nature of payment

Food and Beverage
$191

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
91
Patients
86
Total drug cost
$526
Drug Type Claims Patients Total cost
Pantoprazole Sodium Generic 25 23 $164
Prednisone Generic 24 21 $53
Hydrocodone-Acetaminophen (Hydrocodone/Acetaminophen) Brand 15 15 $82
Cephalexin Generic 14 14 $80
Amoxicillin-Clavulanate Potass (Amoxicillin/Potassium Clav) Brand 13 13 $146

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Mark Diamond's medical specialty?
Dr. Mark Diamond practices Hospitalist Physician in Joliet, IL.
Where does Dr. Mark Diamond practice?
Dr. Mark Diamond practices at 2100 Glenwood Ave, Joliet, IL 604355487. Office phone: 8157252121.
What is Dr. Mark Diamond's NPI?
Dr. Mark Diamond's National Provider Identifier (NPI) is 1265402804, issued by NPPES.
Does Dr. Mark Diamond accept Medicare assignment?
Yes. Dr. Mark Diamond accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Mark Diamond commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with moderate levelof medical decision making (HCPCS 99233); Hospital discharge day management (HCPCS 99239); Initial hospital care with moderate level of medical decision making (HCPCS 99223). Source: CMS Medicare Physician & Other Practitioners file.