Paul O'Brien, M.D.
NPI 1821007220 · Emergency Medicine Physician · Prince Frederick, MD
Enrolled with Medicare as Practitioner - Emergency Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Paul O'Brien, M.D. is a Emergency Medicine Physician provider in Prince Frederick, MD (NPI 1821007220).
Provider details
- NPI number
- 1821007220
- Entity type
- Individual
- Primary specialty
- Emergency Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- D0064665 (MD)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
19 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
874 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) |
|---|---|---|
| Emergency Department Visit With High Level of Medical Decision Making99285 | 480 | $174 |
| Routine Electrocardiogram (ecg) Using at Least 12 Leads With Interpretation and Report Only93010 | 206 | $8 |
| Critical Care, First 30-74 Minutes99291 | 87 | $210 |
| Emergency Department Visit With Moderate Level of Medical Decision Making99284 | 85 | $120 |
| Emergency Department Visit With Low Level of Medical Decision Making99283 | 16 | $71 |
Typical Medicare-allowed amounts for these services range $8–$210 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote 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.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 15 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Prednisone | 222 | 211 |
| Cyclobenzaprine Hcl | 109 | 104 |
| Doxycycline Hyclate | 79 | 78 |
| Oxycodone Hcl/Acetaminophenbrand: Oxycodone-Acetaminophen | 74 | 66 |
| Ondansetron Hcl | 62 | 60 |
| Albuterol Sulfatebrand: Albuterol Sulfate Hfa | 36 | 36 |
| Sulfamethoxazole/Trimethoprimbrand: Sulfamethoxazole-Trimethoprim |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-08-05
- Last updated
- 2007-07-08
Frequently asked questions
- What is Paul O'Brien's NPI number?
- Paul O'Brien's National Provider Identifier (NPI) is 1821007220, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Paul O'Brien's specialty?
- Paul O'Brien is listed in the NPPES registry with a primary specialty of Emergency Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Paul O'Brien located?
- Paul O'Brien's practice location on file with NPPES is 100 Hospital Rd, Prince Frederick, MD 20678-4017.
- What is Paul O'Brien's phone number?
- The practice phone number listed in the NPPES registry for Paul O'Brien is (301) 855-1012.
- Does Paul O'Brien accept Medicare?
- Paul 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 Paul O'Brien's NPI active?
- Yes — Paul O'Brien's NPI (1821007220) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.