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Edit this profileWilliam C. O'Callahan, MD practices emergency medicine in Holden, MA. William is a 1990 graduate of University of Massachusetts Medical School. According to Medicare claims data, William cared for 958 Medicare patients across 988 services. The services billed most often include established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more, established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more, and x-ray of chest, 2 views. The provider's National Provider Identifier (NPI) is 1114964186.
Factual summary compiled by Guide.md from public records; not written by this provider.
Exactly as CMS reports it (National Downloadable File, Opt-Out Affidavits, Order & Referring). Not an insurance directory; confirm coverage with the office.
5 SHREWSBURY ST STE D
Holden, MA 01520
688 Bliss Rd
Longmeadow, MA 01106
2040 Boston Rd Ste 5
Wilbraham, MA 01095
Within Emergency Medicine generally. Availability varies by clinician, training and location — this profile has not been claimed, so nothing here is a personal claim by the provider.
Bites & Stings
Brain & Nerves
Endocrine & Metabolic
Eye Care
Injuries & Trauma
Rashes & allergy
Skin & Infections
Urinary & Bladder
Women's Health
Abdomen & Digestion
Allergy & Immune
Allergy & Immunology
Blood & Circulation
Breathing
Digestion & Stomach
Ear, Nose & Throat
Environmental
Eye Emergency
General Emergency
Heart & Chest
Heart & Circulation
Heart & Lungs
Infections & Illness
Lungs & Breathing
Men's Health
Poisoning & Environmental
Poisoning & Toxins
Spine & Back
Urinary & Kidney
Abdominal Procedures
Breathing & Airway
Critical Care
Diagnostic testing
Diagnostics
Ear, Nose & Throat
Eye & ENT
Heart & Diagnostics
Imaging & Diagnostics
Injections & Vaccines
Kidney Care
Lung & Respiratory
Medications
Mental Health
Minor Procedures
Minor Trauma
Orthopedics
Poisoning & Toxicology
Specialized Care
Stroke & Vascular
Toxicology
Women's Health
Wound Care
Airway & Breathing
Anesthesia & Sedation
Digestive Care
Eye Care
Heart Care
Orthopedic Procedures
Supportive Care
988 services · 958 patients · 14 distinct codes
| Procedure | Type | Code | Services | Compared with peers |
|---|---|---|---|---|
| X-ray of chest, 2 views | Imaging | 71046 |
121 | More than most peers in Emergency Medicine |
| X-ray of foot, minimum of 3 views | Imaging | 73630 |
14 | Less often than most peers in Emergency Medicine |
| Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report | Treatment | 93000 |
12 | Less often than most peers in Emergency Medicine |
| Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more | Office visit | 99213 |
188 | More often than most peers in Emergency Medicine |
| Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more | Office visit | 99214 |
179 | More often than most peers in Emergency Medicine |
| New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more | Office visit | 99203 |
88 | More often than most peers in Emergency Medicine |
| New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more | Office visit | 99204 |
86 | More often than most peers in Emergency Medicine |
| 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 | Lab test | 87636 |
66 | More often than most peers in Emergency Medicine |
| Detection test by nucleic acid for multiple types of respiratory virus, multiple types or subtypes, 3-5 targets | Lab test | 87631 |
62 | Too few peers to compare |
| Amplifed dna or rna probe detection of severe acute respiratory syndrome coronavirus 2 (covid-19) antigen | Lab test | 87635 |
51 | More often than most peers in Emergency Medicine |
Source: CMS Medicare public data. Shows how often procedures were billed — not quality of care or patient satisfaction.
Dr. O'Callahan is an emergency physician in Holden, MA. That is the designation recorded for this NPI in the federal registry, where it is listed as “Emergency Medicine”.
NPI registry
Dr. O'Callahan is listed at 5 Shrewsbury St Ste D, Holden, MA 01520. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
The number on file is (508) 829-3800. Contact the office directly to confirm availability and scheduling.
NPI registry
Dr. O'Callahan's National Provider Identifier is 1114964186. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.
NPI registry
Dr. O'Callahan attended University of Massachusetts Medical School, graduating in 1990. This comes from the CMS National Downloadable File.
CMS public data
Dr. O'Callahan has 36 years experience. Calculated from a graduation year of 1990, reported in the CMS National Downloadable File.
CMS public data
According to Medicare billing data, Dr. O'Callahan performs imaging including x-ray of chest, 2 views and x-ray of foot, minimum of 3 views; provides treatments such as routine electrocardiogram using at least 12 leads with interpretation and report, alongside routine visits and testing. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Not yet. This profile is built from public federal data and has not been confirmed by Dr. O'Callahan. If this is you, claiming it is free.
Guide.md
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