Quick answers
- Does Catherine B. O Brien accept Medicare assignment?
- Yes. Medicare's clinician data says Catherine B. 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 Catherine B. O Brien see?
- In 2024, CMS data shows 112 Original Medicare patients and 559 services for Catherine B. O Brien. This counts Original Medicare only and measures volume, not quality.
- What is Catherine B. O Brien's NPI number?
- 1578513107. 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 Catherine B. 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 | 112 |
|---|---|
| Services billed to Medicare | 559 |
| Different services or procedures | 12 |
| Participating Medicare provider | Yes |
| Average age of these patients | 74 |
Most frequent services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)190 services
- Psychotherapy with evaluation and management visit, 30 minutes (90833)156 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)129 services
- Psychiatric diagnostic evaluation with medical services (90792)25 services
- Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes (99222)25 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 cholesterol75%
- Anxiety75%
- High blood pressure67%
- Depression54%
- Arthritis44%
- Ischemic heart disease30%
Hospitals where Catherine B. O Brien works
Medicare's Facility Affiliation Data lists Catherine B. 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.
- Suny/Stony Brook University HospitalStony Brook, NY · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 330393
Practice locations
Addresses where Catherine B. O Brien is enrolled with Medicare (CMS data updated October 2, 2026).
- 325 Meeting House LnSouthampton, NY 11968 (631) 283‑4048
- 518 Montauk Hwy, Suite 102Amagansett, NY 11930 (631) 267‑5373
Group practices
Medicare enrollment lists Catherine B. O Brien as a member of this group (CMS data updated October 2, 2026).
- Meeting House Lane Medical Practice PC124 clinicians in the group
Specialties
- Nurse Practitionerprimary
Other nurse practitioners in Southampton
Clinicians with the same Medicare primary specialty in Southampton, NY — not a recommendation.
Other clinicians in Meeting House Lane Medical Practice PC
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| School | State University Of New York At Stony Brook, School Of Medicine |
|---|---|
| Graduation year | 1995 |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1578513107 |
| 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