Doctor profile · Federal record
Dr. Mark O'Connor, M.D.
Endocrinology, Diabetes & Metabolism Physician (CMS: Endocrinology) · Worcester, MA
- NPI 1518300284
- Accepts Medicare
- MIPS 89.0 / 100 · 2023
- 13 yrs in practice
- Male
- Group practice
- No sanctions
Practice & contact
Operates at 2 locations .
- Primary practice
-
55 Lake Ave N
Worcester, MA 016550002
(508) 334-3206
fax (774) 442-4668 - Additional location
-
100 Hospital RD
Leominster, MA 014532253
(978) 466-4580
fax (978) 466-4585 - Mailing address
-
Po Box 415348
Boston, MA 022415348
Credentials & registration
- NPI registered
- April 2013 — 13 yrs on file
- Profile last updated
- March 30, 2021
- Year of graduation
- 2013 — 13 yrs since
- Specialty taxonomy
- 207RE0101X — NUCC code
- State license (1)
- Massachusetts #266640
Federal sanctions & exclusions
No sanctions, exclusions or revocations on file
Checked against OIG LEIE on NPI 1518300284. Last verified May 11, 2026.Medicare procedures · 2023
Top services delivered
Total services
366
Distinct HCPCS
4
Medicare allowed
$35,491
| HCPCS | Description | Services | Patients | Avg allowed | |
|---|---|---|---|---|---|
99214 |
Established patient office or other outpatient visit, 30-39 minutes | 242 | 201 | $99 | |
95251 |
Continuous monitoring of blood sugar level in tissue fluid using sensor under skin with interpretation and report | 55 | 47 | $35 | |
99204 |
New patient office or other outpatient visit, 45-59 minutes | 44 | 44 | $136 | |
99215 |
Established patient office or other outpatient visit, 40-54 minutes | 25 | 23 | $146 |
In context: peer comparison
Among 18 peers in this city , average services per provider: 102. This provider delivers 3.6× the peer median.Medicare Part D · 2023
Top prescriptions
Total claims
1,828
Patients
538
Total drug cost
$1,189,684
| Drug | Type | Claims | Patients | Total cost |
|---|---|---|---|---|
| Trulicity (Dulaglutide) | Brand | 477 | 101 | $551,741 |
| Jardiance (Empagliflozin) | Brand | 197 | 54 | $192,815 |
| Metformin Hcl Er (Metformin Hcl) | Brand | 190 | 69 | $4,270 |
| Ozempic (Semaglutide) | Brand | 157 | 38 | $186,765 |
| Metformin Hcl | Generic | 144 | 54 | $2,307 |
| Glipizide Er (Glipizide) | Brand | 121 | 50 | $3,679 |
| Lantus Solostar (Insulin Glargine,hum.Rec.Anlog) | Brand | 98 | 34 | $63,745 |
| Atorvastatin Calcium | Generic | 78 | 28 | $1,458 |
| Mounjaro (Tirzepatide) | Brand | 68 | 21 | $84,953 |
| Levothyroxine Sodium | Generic | 65 | 15 | $1,609 |
Hospital affiliations
Frequently asked questions
What is Dr. Mark O'Connor's medical specialty?
Dr. Mark O'Connor practices Endocrinology, Diabetes & Metabolism Physician in Worcester, MA.
Where does Dr. Mark O'Connor practice?
Dr. Mark O'Connor practices at 55 Lake Ave N, Worcester, MA 016550002. Office phone: 5083343206.
What is Dr. Mark O'Connor's NPI?
Dr. Mark O'Connor's National Provider Identifier (NPI) is 1518300284, issued by NPPES.
Does Dr. Mark O'Connor accept Medicare assignment?
Yes. Dr. Mark O'Connor accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Mark O'Connor commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99214); Continuous monitoring of blood sugar level in tissue fluid using sensor under skin with interpretation and report (HCPCS 95251); New patient office or other outpatient visit (HCPCS 99204). Source: CMS Medicare Physician & Other Practitioners file.