Dennis O'Brien, PAC
NPI 1407895956 · Medical Physician Assistant · Springfield, MA
Enrolled with Medicare as Practitioner - Physician Assistant · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Dennis O'Brien, PAC is a Medical Physician Assistant provider in Springfield, MA (NPI 1407895956).
Provider details
- NPI number
- 1407895956
- Entity type
- Individual
- Primary specialty
- Medical Physician AssistantPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- PAC
- Sex
- Male
- Sole proprietor
- No
- License
- PA4779 (MA)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
20 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
291 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 111 | $66 |
| Subsequent Hospital Care With Straightforward Or Low Level of Medical Decision Making, Per Day, If Using Time, at Least 25 Minutes99231 | 83 | $41 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 43 | $99 |
| Initial Hospital Care With Straightforward Or Low-Level Medical Decision Making, If Using Time, at Least 55 Minutes99222 | 32 | $109 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 22 | $145 |
Typical Medicare-allowed amounts for these services range $41–$145 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-06-06
- Last updated
- 2019-12-16
- Certified
- 2019-12-16
Frequently asked questions
- What is Dennis O'Brien's NPI number?
- Dennis O'Brien's National Provider Identifier (NPI) is 1407895956, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Dennis O'Brien's specialty?
- Dennis O'Brien is listed in the NPPES registry with a primary specialty of Medical Physician Assistant (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Dennis O'Brien located?
- Dennis O'Brien's practice location on file with NPPES is 3300 Main St, Springfield, MA 01199-1619.
- What is Dennis O'Brien's phone number?
- The practice phone number listed in the NPPES registry for Dennis O'Brien is (413) 794-7033.
- Does Dennis O'Brien accept Medicare?
- Dennis O'Brien is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Dennis O'Brien's NPI active?
- Yes — Dennis O'Brien's NPI (1407895956) is active in the NPPES registry as of the last update on 2019-12-16.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.