2026 NPPES data Nephrology Physician NPI 1619902756 MD
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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.

Federal data — no proprietary rating. We show these CMS records as-is — no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
508
Medicare Part D claims · 59 beneficiaries · Nephrology Physician avg: 1K
MIPS score
79.4/100
▼ 4 pts below national avg 83.1 · Above neutral
Compiled from official public sources by the PlainDoctor editorial team.

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

0–10: 8,684 scored providers (2%). Below this entry. 10–20: 3,008 scored providers (1%). Below this entry. 20–30: 3,069 scored providers (1%). Below this entry. 30–40: 2,746 scored providers (1%). Below this entry. 40–50: 2,928 scored providers (1%). Below this entry. 50–60: 5,882 scored providers (1%). Below this entry. 60–70: 13,906 scored providers (3%). Below this entry. 70–80: 118,074 scored providers (25%). This entry sits in this band. 80–90: 129,887 scored providers (27%). Above this entry. 90–100: 189,403 scored providers (40%). Above this entry. This provider 0 100 every MIPS-scored clinician, bucketed by value

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

Lower volume · High qualityHigh volume · High qualityLower volume · Lower qualityHigh volume · Lower quality0255075100024.148.372.496.6Part D claim volume — percentile in specialtyMIPS quality — percentilePart D claim volume — percentile in specialty: 30 · MIPS quality — percentile: 92Part D claim volume — percentile in specialty: 18 · MIPS quality — percentile: 85Part D claim volume — percentile in specialty: 38 · MIPS quality — percentile: 50Part D claim volume — percentile in specialty: 67 · MIPS quality — percentile: 42Part D claim volume — percentile in specialty: 42 · MIPS quality — percentile: 92Part D claim volume — percentile in specialty: 12 · MIPS quality — percentile: 23Part D claim volume — percentile in specialty: 87 · MIPS quality — percentile: 68Part D claim volume — percentile in specialty: 8 · MIPS quality — percentile: 25Part D claim volume — percentile in specialty: 10 · MIPS quality — percentile: 80Part D claim volume — percentile in specialty: 98 · MIPS quality — percentile: 88Part D claim volume — percentile in specialty: 22 · MIPS quality — percentile: 75Part D claim volume — percentile in specialty: 65 · MIPS quality — percentile: 57Part D claim volume — percentile in specialty: 95 · MIPS quality — percentile: 52Part D claim volume — percentile in specialty: 55 · MIPS quality — percentile: 3Part D claim volume — percentile in specialty: 62 · MIPS quality — percentile: 73Part D claim volume — percentile in specialty: 7 · MIPS quality — percentile: 58Part D claim volume — percentile in specialty: 58 · MIPS quality — percentile: 33Part D claim volume — percentile in specialty: 63 · MIPS quality — percentile: 10Part D claim volume — percentile in specialty: 93 · MIPS quality — percentile: 53Part D claim volume — percentile in specialty: 92 · MIPS quality — percentile: 47Part D claim volume — percentile in specialty: 53 · MIPS quality — percentile: 12Part D claim volume — percentile in specialty: 37 · MIPS quality — percentile: 28Part D claim volume — percentile in specialty: 25 · MIPS quality — percentile: 67Part D claim volume — percentile in specialty: 5 · MIPS quality — percentile: 45Part D claim volume — percentile in specialty: 77 · MIPS quality — percentile: 92Part D claim volume — percentile in specialty: 97 · MIPS quality — percentile: 55Part D claim volume — percentile in specialty: 45 · MIPS quality — percentile: 8Part D claim volume — percentile in specialty: 83 · MIPS quality — percentile: 70Part D claim volume — percentile in specialty: 0 · MIPS quality — percentile: 77Part D claim volume — percentile in specialty: 82 · MIPS quality — percentile: 63Part D claim volume — percentile in specialty: 23 · MIPS quality — percentile: 62Part D claim volume — percentile in specialty: 75 · MIPS quality — percentile: 92Part D claim volume — percentile in specialty: 70 · MIPS quality — percentile: 65Part D claim volume — percentile in specialty: 35 · MIPS quality — percentile: 13Part D claim volume — percentile in specialty: 100 · MIPS quality — percentile: 78Part D claim volume — percentile in specialty: 57 · MIPS quality — percentile: 83Part D claim volume — percentile in specialty: 15 · MIPS quality — percentile: 15Part D claim volume — percentile in specialty: 88 · MIPS quality — percentile: 48Part D claim volume — percentile in specialty: 20 · MIPS quality — percentile: 92Part D claim volume — percentile in specialty: 12 · MIPS quality — percentile: 28Part D claim volume — percentile in specialty: 78 · MIPS quality — percentile: 20Part D claim volume — percentile in specialty: 40 · MIPS quality — percentile: 70Part D claim volume — percentile in specialty: 50 · MIPS quality — percentile: 18Part D claim volume — percentile in specialty: 90 · MIPS quality — percentile: 5Part D claim volume — percentile in specialty: 60 · MIPS quality — percentile: 2Part D claim volume — percentile in specialty: 3 · MIPS quality — percentile: 37Part D claim volume — percentile in specialty: 68 · MIPS quality — percentile: 85Part D claim volume — percentile in specialty: 73 · MIPS quality — percentile: 35Part D claim volume — percentile in specialty: 2 · MIPS quality — percentile: 92Part D claim volume — percentile in specialty: 43 · MIPS quality — percentile: 28Part D claim volume — percentile in specialty: 27 · MIPS quality — percentile: 40Part D claim volume — percentile in specialty: 85 · MIPS quality — percentile: 0Part D claim volume — percentile in specialty: 47 · MIPS quality — percentile: 90Part D claim volume — percentile in specialty: 32 · MIPS quality — percentile: 17Part D claim volume — percentile in specialty: 80 · MIPS quality — percentile: 80Part D claim volume — percentile in specialty: 52 · MIPS quality — percentile: 7Part D claim volume — percentile in specialty: 72 · MIPS quality — percentile: 20Part D claim volume — percentile in specialty: 28 · MIPS quality — percentile: 43Part D claim volume — percentile in specialty: 17 · MIPS quality — percentile: 58Part D claim volume — percentile in specialty: 48 · MIPS quality — percentile: 25Karen Warburton, MD — Part D claim volume — percentile in specialty: 25 · MIPS quality — percentile: 44
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.

Board certification likely (heuristic — not verified)

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 average

NPI registry status

Active

Issued 07/11/2006

NPI 1619902756

Primary specialty

Nephrology Physician

Mid-sized

10,534 US NPIs in this specialty

Medicare Part D claims

508 65% vs specialty avg

2023 prescription claims

Specialty avg: 1,454

MIPS final score

79.4/100 3.7 pts vs avg

Above neutral band

vs 83.1 national avg

Specialty distribution in Virginia

How Nephrology Physician compares to other specialties among Virginia providers

Virginia providers

Largest specialties in Virginia (% of in-state providers)

Behavior Technician — 5.2%Behavior Technician5.2%Clinical Social Worker — 5.1%Clinical Social Worker5.1%Student in an Organized Health Care Education/Training Program — 4.7%Student in an Organized Health Care Education/Training Program4.7%Physical Therapist — 4.6%Physical Therapist4.6%Pharmacist — 4.5%Pharmacist4.5%Professional Counselor — 4%Professional Counselor4%Nephrology Physician — 0.2%Nephrology Physician0.2%
Largest specialties in Virginia (% of in-state providers)

Medicare quality performance — MIPS

Karen Warburton, MD's 2023 MIPS final score plotted against the Nephrology Physician national average

Near 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

0%100%National avg83%79.4%
MIPS final score (Nephrology Physician) — 79.4/100 vs national avg 83.1

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

1300 JEFFERSON PARK AVE
Charlottesville, VA 22903

Provider Details

NPI 1619902756
Specialty Nephrology Physician
Credentials MD
Gender Female
NPI Issued 07/11/2006

CMS Quality Score (MIPS)

Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.

79.3949
Final Score
Avg: 83.1
73.6607
Quality
57.6556
Cost
100
Promoting Interoperability

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.

University OF Virginia Physicians Group
Charlottesville, VA

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.

508
Total Claims
$330K
Total Drug Cost
59
Medicare Beneficiaries

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

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
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.

10,534
Nephrology Physician Providers in US
55
States with Nephrology Physician
1,454
Avg Claims per Provider

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.

Frequently Asked Questions

What is Karen Warburton, MD's specialty?
Karen Warburton, MD specializes in Nephrology Physician and practices in Charlottesville, Virginia. Credentials: MD.
How much does Karen Warburton, MD prescribe under Medicare Part D?
In 2023, Karen Warburton, MD wrote 508 Medicare Part D claims totaling $330K in drug costs for 59 beneficiaries.
What is Karen Warburton, MD's Medicare quality score?
Karen Warburton, MD has a CMS MIPS Final Score of 79.4/100 (Quality: 73.7, Cost: 57.7). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is Karen Warburton, MD located?
Karen Warburton, MD is located at 1300 JEFFERSON PARK AVE, Charlottesville, VA, 22903. Phone: (434) 924-1984.
What is Karen Warburton, MD's NPI number?
Karen Warburton, MD's National Provider Identifier (NPI) is 1619902756, issued on 07/11/2006.
How many Nephrology Physician providers are there in the US?
There are 10,534 Nephrology Physician providers across 55 states in the US. The average Nephrology Physician provider writes 1,454 Medicare Part D claims per year.
What drugs does Karen Warburton, MD prescribe most often?
Based on 2023 Medicare Part D data, Karen Warburton, MD's most frequently prescribed drugs include Prednisone, Carvedilol, Amlodipine Besylate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Karen Warburton, MD accept Medicare?
Karen Warburton, MD appears in CMS Medicare data with 508 Part D claims and 59 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Karen Warburton, MD's credentials?
Karen Warburton, MD's NPI is 1619902756 with credentials MD. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.

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

Compiled from official public sources by the PlainDoctor editorial team.