Karen Warburton, MD
Nephrology Physician in Charlottesville, Virginia. This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers — including 10,534 in Nephrology Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration — see our methodology.
What the federal data shows
Karen Warburton, MD reported a CMS MIPS final score of 79.4/100 — below the 83.1 national average — and filed 508 Medicare Part D claims in 2023.
- 79.4/100
- MIPS score · -4 vs avg
- 508
- Part D claims, 2023
- Likely
- board-certified (heuristic)
Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) — no proprietary rating or editorial opinion is applied.
Karen Warburton, MD's MIPS score vs every scored U.S. clinician
CMS Merit-based Incentive Payment System (MIPS) final score, 2023 — the federal quality measure
79 30th percentile higher than 30% of 477,587 scored providers
Each bar is a band; taller bars hold more scored providers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source CMS Merit-based Incentive Payment System (MIPS) · 2023
Where Karen Warburton, MD sits
This provider among nephrology physician peers
Across the 2,476 nephrology physician providers who report both Medicare Part D prescribing and a MIPS quality score, Karen Warburton, MD writes more Part D claims than 25% of them and scores higher on MIPS quality than 44% — placing this provider in the lower-volume, lower-quality quadrant. Volume reflects patient-panel size and specialty, not quality; the two axes are independent.
Part D claim volume vs MIPS quality, by specialty percentile
Each dot is one nephrology physician peer from a representative sample of 60; the gold marker is Karen Warburton, MD. Source: CMS Medicare Part D Prescriber data and the CMS Merit-based Incentive Payment System, 2023.
Karen Warburton, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Karen Warburton, MD?
Near national averagePrimary specialty
Medicare Part D claims
MIPS final score
Specialty distribution in Virginia
How Nephrology Physician compares to other specialties among Virginia providers
Largest specialties in Virginia (% of in-state providers)
Nephrology Physician ranks #80 among Virginia's specialties (0.2% of in-state providers)
Each bar is a specialty's share of the Virginia provider total, by primary NUCC taxonomy. The highlighted bar is Nephrology Physician; the long tail of smaller specialties is omitted for legibility.
Medicare quality performance — MIPS
Karen Warburton, MD's 2023 MIPS final score plotted against the Nephrology Physician national average
- MIPS Final Score
- 79.4/100
- vs 83.1 national avg · 2023 performance year
MIPS final score (Nephrology Physician) — 79.4/100 vs national avg 83.1
Quality benchmarks
- National MIPS avg 2023 reporting year
- Quality dim CMS Quality category
- Cost dim CMS Cost category
- Specialty volume Nephrology Physician US NPIs
79.4/100 MIPS final score — 3.7 pts below the 83.1 national average
Quality, Cost, Promoting Interoperability, and Improvement Activities composite score for the 2023 performance year. Specialty: Nephrology Physician. Quality dim: 73.7. Cost dim: 57.7.
The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.
Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).
Karen Warburton, MD appears in the CMS NPPES registry as a Nephrology Physician provider holding MD credentials at 1300 JEFFERSON PARK AVE, Charlottesville, VA, 22903, with a listed phone of (434) 924-1984. NPI 1619902756 was issued on 07/11/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Warburton most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.
Medicare Part D records for calendar year 2023 show 508 prescription claims written by this provider, covering 59 Medicare beneficiaries and totaling roughly $330K in drug spend. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 79.4/100 for the 2023 performance year (Quality 73.7, Cost 57.7), compared with the national average of 83.1.
Nephrology Physician is a mid-sized specialty nationwide, with 10,534 enrolled providers across 55 states and an average of 1,454 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline. Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist — always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.
Practice Address
Provider Details
| NPI | 1619902756 |
|---|---|
| Specialty | Nephrology Physician |
| Credentials | MD |
| Gender | Female |
| NPI Issued | 07/11/2006 |
Verify this provider's license
PlainDoctor pulls this profile from the CMS NPPES public registry. Confirm Karen Warburton, MD's current license status, disciplinary history, and board certifications with the Virginia Board of Medicine in Virginia before relying on this page for a clinical or care decision.
How we sourced this profile
CMS Quality Score (MIPS)
Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.
Reporting: Group practice
Hospital and facility affiliations
Facilities where Karen Warburton, MD bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" — a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
Prescribing Breakdown
- 30-Day Fills
- 1,150
- Total Day Supply
- 34,180
- Generic Drug Cost
- $17K
Patient Demographics
- Average Patient Age
- 61.2 years
- Avg HCC Risk Score
- 3.53
- Gender Split
- 56% female / 44% male
- Age Distribution
- <65: 30, 65-74: 23, 75-84: N/A, 85+: N/A
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Karen Warburton, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Prednisone
Prednisone
79 claims
- Carvedilol
Carvedilol
56 claims
- Amlodipine Besylate 28
Amlodipine Besylate
28 claims
- Pravastatin Sodium 27
Pravastatin Sodium
27 claims
- Nifedipine Er 24
Nifedipine Er
24 claims
- Cinacalcet Hcl 23
Cinacalcet Hcl
23 claims
- Losartan Potassium 21
Losartan Potassium
21 claims
- Furosemide 19
Furosemide
19 claims
| Drug | Claims |
|---|---|
| Prednisone | 79 |
| Carvedilol | 56 |
| Amlodipine Besylate | 28 |
| Pravastatin Sodium | 27 |
| Nifedipine Er Nifedipine | 24 |
| Cinacalcet Hcl | 23 |
| Losartan Potassium | 21 |
| Furosemide | 19 |
| Famotidine | 17 |
| Pantoprazole Sodium | 15 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Nephrology Physician Overview
How Karen Warburton, MD fits within the Nephrology Physician landscape nationally.
Karen Warburton, MD's 508 claims are below the specialty average of 1,454.
Nearby Nephrology Physician Providers in Virginia
Other clinicians with the same primary specialty enrolled in Virginia, drawn from the same CMS NPPES roster as Warburton.
Compare Nephrology Physician nationally: see state-by-state distribution →
Before you book an appointment
Use this federal record as your verification checklist, not as a recommendation.
- Confirm the NPI record is current in the official CMS registry — providers update their own NPPES details, and moves can lag. Verify this NPI
- Check the active license and any disciplinary history with the Virginia medical board — federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Nephrology Physician peer on Medicare volume and prescribing patterns. Compare providers
Medicare Part D and MIPS figures describe practice patterns in federal programs only — they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.
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Frequently Asked Questions
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Data Sources
- Provider Directory
- CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
- Specialty Classification
- NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
- Prescribing Data
- CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
- Quality Performance
- CMS Merit-based Incentive Payment System (MIPS) — 2023 performance year.
- Limitations
- Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.
See our complete data methodology for details on how we collect and process government data.
Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).
Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology