Doctor profile · Federal record
Dr. William O'Callahan, MD
Emergency Medicine Physician (CMS: Emergency Medicine) · Holden, MA
- NPI 1114964186
- Accepts Medicare
- 36 yrs in practice
- Male
- Group practice
- No sanctions
Practice & contact
Operates at 4 locations .
- Primary practice
-
5 Shrewsbury St Ste D
Holden, MA 015201960
(508) 829-3800
fax (508) 829-3802 - Additional location
-
2040 Boston RD Ste 5
Wilbraham, MA 010951380
(413) 599-3800
fax (413) 279-1900 - Additional location
-
2040 Boston Road, Ste 5
Wilbraham, MA 010951380
(413) 599-3800
fax (413) 279-1900 - Additional location
-
688 Bliss Road
Longmeadow, MA 011061534
(413) 567-0011
fax (413) 567-0013
Show 1 more location
Credentials & registration
- NPI registered
- May 2006 — 20 yrs on file
- Profile last updated
- January 21, 2025
- Year of graduation
- 1990 — 36 yrs since
- Specialty taxonomy
- 207P00000X — NUCC code
- State license (1)
- Massachusetts #79001
Federal sanctions & exclusions
No sanctions, exclusions or revocations on file
Checked against OIG LEIE on NPI 1114964186. Last verified May 11, 2026.Medicare procedures · 2023
Top services delivered
Total services
759
Distinct HCPCS
10
Medicare allowed
$72,008
| HCPCS | Description | Services | Patients | Avg allowed | |
|---|---|---|---|---|---|
99213 |
Established patient office or other outpatient visit, 20-29 minutes | 217 | 202 | $93 | |
99203 |
New patient office or other outpatient visit, 30-44 minutes | 101 | 101 | $115 | |
99214 |
Established patient office or other outpatient visit, 30-39 minutes | 89 | 87 | $129 | |
87636 |
Detection test by multiplex amplified probe technique for severe acute respiratory syndrome coronavirus 2 (sars-cov-2) (covid-19) and influenza virus types a and b | 87 | 86 | $140 | |
71046 |
X-ray of chest, 2 views | 85 | 78 | $32 | |
99204 |
New patient office or other outpatient visit, 45-59 minutes | 47 | 47 | $167 | |
87651 |
Detection test by nucleic acid for strep (streptococcus, group a), amplified probe technique | 37 | 36 | $34 | |
81003 |
Automated urinalysis test | 36 | 34 | $2 | |
87631 |
Detection test by nucleic acid for multiple types of respiratory virus, multiple types or subtypes, 3-5 targets | 24 | 24 | $140 | |
87635 |
Amplifed dna or rna probe detection of severe acute respiratory syndrome coronavirus 2 (covid-19) antigen | 21 | 21 | $50 |
In context: peer comparison
Among 5 peers in Holden Emergency Medicine Physician, average services per provider: 55. This provider delivers 14× the peer median.Medicare Part D · 2023
Top prescriptions
Total claims
443
Patients
436
Total drug cost
$3,552
| Drug | Type | Claims | Patients | Total cost |
|---|---|---|---|---|
| Doxycycline Hyclate | Generic | 114 | 111 | $1,116 |
| Azithromycin | Generic | 96 | 95 | $415 |
| Prednisone | Generic | 49 | 49 | $147 |
| Amoxicillin-Clavulanate Potass (Amoxicillin/Potassium Clav) | Brand | 35 | 33 | $340 |
| Ibuprofen | Generic | 35 | 35 | $113 |
| Nitrofurantoin Mono-Macro (Nitrofurantoin Monohyd/M-Cryst) | Brand | 28 | 27 | $328 |
| Paxlovid (Eua) (Nirmatrelvir/Ritonavir) | Brand | 27 | 27 | $259 |
| Cephalexin | Generic | 25 | 25 | $567 |
| Erythromycin (Erythromycin Base) | Brand | 18 | 18 | $199 |
| Naproxen | Generic | 16 | 16 | $67 |
Hospital affiliations
Frequently asked questions
What is Dr. William O'Callahan's medical specialty?
Dr. William O'Callahan practices Emergency Medicine Physician in Holden, MA.
Where does Dr. William O'Callahan practice?
Dr. William O'Callahan practices at 5 Shrewsbury St Ste D, Holden, MA 015201960. Office phone: 5088293800.
What is Dr. William O'Callahan's NPI?
Dr. William O'Callahan's National Provider Identifier (NPI) is 1114964186, issued by NPPES.
Does Dr. William O'Callahan accept Medicare assignment?
Yes. Dr. William O'Callahan accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. William O'Callahan commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99213); New patient office or other outpatient visit (HCPCS 99203); Established patient office or other outpatient visit (HCPCS 99214). Source: CMS Medicare Physician & Other Practitioners file.