Quick answers
- Does Frank Joseph O Brien accept Medicare assignment?
- Yes. Medicare's clinician data says Frank Joseph O Brien accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does Frank Joseph O Brien see?
- In 2024, CMS data shows 165 Original Medicare patients and 1,591 services for Frank Joseph O Brien. This counts Original Medicare only and measures volume, not quality.
- What is Frank Joseph O Brien's NPI number?
- 1144774266. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for Frank Joseph O Brien, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 165 |
|---|---|
| Services billed to Medicare | 1,591 |
| Different services or procedures | 28 |
| Participating Medicare provider | Yes |
| Average age of these patients | 68 |
Most frequent services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)60 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)57 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)38 services
- Dialysis services, 4 or more physician visits per month (20 years or older) (90960)36 services
- Urinalysis, manual test (81002)17 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High blood pressure75%
- High cholesterol75%
- Chronic kidney disease75%
- Diabetes52%
- Arthritis45%
- Ischemic heart disease44%
Hospitals where Frank Joseph O Brien works
Medicare's Facility Affiliation Data lists Frank Joseph O Brien at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- Barnes Jewish HospitalSaint Louis, MO · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 260032
- Barnes-Jewish West County HospitalCreve Coeur, MO · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 260162
- Mercy Hospital SoutheastCape Girardeau, MO · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 260110
- Missouri Baptist Medical CenterSaint Louis, MO · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 260108
Practice locations
Addresses where Frank Joseph O Brien is enrolled with Medicare (CMS data updated October 2, 2026).
- 660 So Euclid Campus Box, 8015 Department of Internal MedicineSt Louis, MO 63110 (314) 273‑0395
Group practices
Medicare enrollment lists Frank Joseph O Brien as a member of this group (CMS data updated October 2, 2026).
- Washington University3,029 clinicians in the group
Specialties
- Nephrologyprimary
- Internal Medicinealso
Other nephrologists in St Louis
Clinicians with the same Medicare primary specialty in St Louis, MO — not a recommendation.
Other clinicians in Washington University
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2006 (20 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1144774266 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians