Quick answers
- Does Margaret A. Greven accept Medicare assignment?
- Yes. Medicare's clinician data says Margaret A. Greven 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 Margaret A. Greven see?
- In 2024, CMS data shows 484 Original Medicare patients and 5,836 services for Margaret A. Greven. This counts Original Medicare only and measures volume, not quality.
- What is Margaret A. Greven's NPI number?
- 1821380874. 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 Margaret A. Greven, 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 | 484 |
|---|---|
| Services billed to Medicare | 5,836 |
| Different services or procedures | 34 |
| Participating Medicare provider | Yes |
| Average age of these patients | 77 |
Most frequent services
- Injection, faricimab-svoa, 0.1 mg (J2777)3,000 services
- Imaging of retina (92134)1,155 services
- Injection of drug into eye (67028)731 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)496 services
- Injection, aflibercept, 1 mg (J0178)166 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%
- Arthritis46%
- Diabetes39%
- Chronic kidney disease33%
- Ischemic heart disease24%
Hospitals where Margaret A. Greven works
Medicare's Facility Affiliation Data lists Margaret A. Greven 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.
- North Carolina Baptist HospitalWinston-Salem, NC · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 340047
- Novant Health Forsyth Medical CenterWinston-Salem, NC · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 340014
Practice locations
Addresses where Margaret A. Greven is enrolled with Medicare (CMS data updated October 2, 2026).
- Medical Ctr BlvdWinston Salem, NC 27157 (336) 716‑2734
Group practices
Medicare enrollment lists Margaret A. Greven as a member of this group (CMS data updated October 2, 2026).
- Wake Forest University Health Sciences2,645 clinicians in the group
Specialties
- Ophthalmologyprimary
Other ophthalmologists in Winston Salem
Clinicians with the same Medicare primary specialty in Winston Salem, NC — not a recommendation.
Other clinicians in Wake Forest University Health Sciences
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2011 (15 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1821380874 |
| 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