Quick answers
- Does Megan L. O'Brien accept Medicare assignment?
- Yes. Medicare's clinician data says Megan L. 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 Megan L. O'Brien see?
- In 2024, CMS data shows 1,711 Original Medicare patients and 2,456 services for Megan L. O'Brien. This counts Original Medicare only and measures volume, not quality.
- What is Megan L. O'Brien's NPI number?
- 1659804193. 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 Megan L. 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 | 1,711 |
|---|---|
| Services billed to Medicare | 2,456 |
| Different services or procedures | 96 |
| Participating Medicare provider | Yes |
| Average age of these patients | 76 |
Most frequent services
- X-ray of chest, 1 view (71045)421 services
- X-ray of chest, 2 views (71046)414 services
- Ct scan of chest without contrast (71250)234 services
- Ct scan of abdomen and pelvis with contrast (74177)215 services
- Ct scan of chest with contrast (71260)125 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%
- Arthritis66%
- Ischemic heart disease41%
- Chronic kidney disease38%
- Anxiety36%
Hospitals where Megan L. O'Brien works
Medicare's Facility Affiliation Data lists Megan L. 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 St Peters HospitalSaint Peters, MO · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 260191
- Christian Hospital NortheastSaint Louis, MO · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 260180
- Missouri Baptist Medical CenterSaint Louis, MO · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 260108
- Progress West HospitalOfallon, MO · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 260219
Practice locations
Addresses where Megan L. O'Brien is enrolled with Medicare (CMS data updated October 2, 2026).
- 1785 Clarkson RdChesterfield, MO 63017 (636) 681‑1540
- 510 S Kingshighway BlvdSaint Louis, MO 63110
Group practices
Medicare enrollment lists Megan L. O'Brien as a member of these groups (CMS data updated October 2, 2026).
- Washington University3,029 clinicians in the group
- BJC Outpatient Imaging LLC25 clinicians in the group
Specialties
- Diagnostic Radiologyprimary
Other radiologists in Chesterfield
Clinicians with the same Medicare primary specialty in Chesterfield, 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 | DO |
|---|---|
| Medical school | At Still University Of Health Sciences, College Of Osteo Med, Kirksville |
| Graduation year | 2017 (9 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1659804193 |
| 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