NPI registry status
Active
2026 NPPES data Gastroenterology Physician NPI 1548384167 M.D.
Verify on CMS → Karen Simon, M.D.
Gastroenterology Physician in Oxnard, California.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 16,601 in Gastroenterology 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
696
Medicare Part D claims · 176 beneficiaries · Gastroenterology Physician avg: 833
Generic prescribing
79%
generic claims · 21% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
84/100
▲ 1 pts above national avg 83.1 · Above neutral
Industry payments
$2.1K
92 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Karen Simon, M.D. reported a CMS MIPS final score of 84/100 - above the 83.1 national average - and filed 696 Medicare Part D claims in 2023.
- 84/100
- MIPS score · +1 vs avg
- 696
- Part D claims, 2023
- 79%
- generic prescribing
- 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 Simon, M.D.'s MIPS score vs every scored U.S. clinician
CMS Merit-based Incentive Payment System (MIPS) final score, 2023, the federal quality measure
84 42nd percentile higher than 42% 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 Simon, M.D. sits
This provider among gastroenterology physician peers
Across the 5,957 gastroenterology physician providers who report both Medicare Part D prescribing and a MIPS quality score, Karen Simon, M.D. writes more Part D claims than 45% of them and scores higher on MIPS quality than 49% - 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 gastroenterology physician peer from a representative sample of 60; the gold marker is Karen Simon, M.D.. Source: CMS Medicare Part D Prescriber data and the CMS Merit-based Incentive Payment System, 2023.
✓
Board certification likely (heuristic, not verified)
Karen Simon, M.D. 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 Simon, M.D.?
Near national averagePrimary specialty
Gastroenterology Physician
Medicare Part D claims
696 16% vs specialty avg
MIPS final score
84/100 0.9 pts vs avg
Specialty distribution in California
How Gastroenterology Physician compares to other specialties among California providers
Medicare quality performance, MIPS
Karen Simon, M.D.'s 2023 MIPS final score plotted against the Gastroenterology Physician national average
- MIPS Final Score
- 84/100
- vs 83.1 national avg · 2023 performance year
MIPS final score (Gastroenterology Physician) - 84/100 vs national avg 83.1
How MIPS and board certification work
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 Simon, M.D. appears in the CMS NPPES registry as a Gastroenterology Physician provider holding M.D. credentials at 2241 WANKEL WAY, Oxnard, CA, 93030, with a listed phone of (805) 983-0521. NPI 1548384167 was issued on 03/19/2007.
Medicare Part D records for calendar year 2023 show 696 prescription claims written by this provider, covering 176 Medicare beneficiaries and totaling roughly $416K in drug spend, split 21% brand-name and 79% generic by claim count. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 84/100 for the 2023 performance year (Quality 79.4), compared with the national average of 83.1.
Gastroenterology Physician is a mid-sized specialty nationwide, with 16,601 enrolled providers across 54 states and an average of 833 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 | 1548384167 |
|---|---|
| Specialty | Gastroenterology Physician |
| Credentials | M.D. |
| Gender | Female |
| NPI Issued | 03/19/2007 |
CMS Quality Score (MIPS)
Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.
83.9994
Final Score
Avg: 83.1
79.4078
Quality
Reporting: Group practice
Hospital and facility affiliations
Facilities where Karen Simon, M.D. 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.
Genesis Healthcare Partners PC
Oxnard, CA
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
Industry payments received (2024) - CMS Open Payments transparency data
The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for Karen Simon, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$2.1K
Largest payer
ABBVIE INC.
Most common payment type
Food and Beverage
Industry payments are not necessarily indicators of bias, they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.
License & disciplinary context - California MBC 2023 annual report
Aggregate state board data only, NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~150K California medical licensees in 2023 - they are NOT specific to Karen Simon, M.D.. To verify Karen Simon, M.D.'s current license status, search the MBC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
576
Total board actions, California 2023
Across 556 cases
3.84
Actions per 1,000 licensees
California statewide rate
probation
Most common action type
186 cases
MBC publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the California disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Brand vs generic prescribing mix · Typical
Karen Simon, M.D. - brand share 21.0%
Gastroenterology Physician average
21% brand-name claims vs 79% generic, on 696 2023 Medicare Part D claims.
The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
696
Total Claims
$416K
Total Drug Cost
176
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,295
- Total Day Supply
- 37,431
- Brand vs Generic
- 21% brand / 79% generic
- Brand Drug Cost
- $344K
- Generic Drug Cost
- $72K
- Antibiotic Claims
- 26
Patient Demographics
- Average Patient Age
- 73.7 years
- Avg HCC Risk Score
- 1.40
- Gender Split
- 82% female / 18% male
- Age Distribution
- <65: 12, 65-74: 86, 75-84: 63, 85+: 15
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Karen Simon, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Pantoprazole Sodium
Pantoprazole Sodium
91 claims
- Omeprazole
Omeprazole
85 claims
- Dexlansoprazole Dr
Dexlansoprazole Dr
38 claims
- Dicyclomine Hcl 32
Dicyclomine Hcl
32 claims
- Famotidine 30
Famotidine
30 claims
- Mesalamine 28
Mesalamine
28 claims
- Linzess 25
Linzess
25 claims
- Budesonide Ec 18
Budesonide Ec
18 claims
| Drug | Claims |
|---|---|
| Pantoprazole Sodium | 91 |
| Omeprazole | 85 |
| Dexlansoprazole Dr Dexlansoprazole | 38 |
| Dicyclomine Hcl | 32 |
| Famotidine | 30 |
| Mesalamine | 28 |
| Linzess Linaclotide | 25 |
| Budesonide Ec Budesonide | 18 |
| Ondansetron Hcl | 18 |
| Creon Lipase/Protease/Amylase | 17 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Gastroenterology Physician Overview
How Karen Simon, M.D. fits within the Gastroenterology Physician landscape nationally.
16,601
Gastroenterology Physician Providers in US
54
States with Gastroenterology Physician
833
Avg Claims per Provider
Karen Simon, M.D.'s 696 claims are below the specialty average of 833.
Nearby Gastroenterology Physician Providers in California
Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as Simon.
Dr. David Aarons
MD
Lodi, CA
Dr. Constante Abaya
MD
Oxnard, CA
Dr. Homan Abdollahzadeh
MD
Palm Springs, CA
Dr. John Abdulian
M.D.
Fresno, CA
Dr. Hussein Abidali
DO
Rancho Cucamonga, CA
Compare Gastroenterology 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 California medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Gastroenterology 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
What is Karen Simon, M.D.'s specialty? ▼
Karen Simon, M.D. specializes in Gastroenterology Physician and practices in Oxnard, California. Credentials: M.D..
How much does Karen Simon, M.D. prescribe under Medicare Part D? ▼
In 2023, Karen Simon, M.D. wrote 696 Medicare Part D claims totaling $416K in drug costs for 176 beneficiaries.
What is Karen Simon, M.D.'s Medicare quality score? ▼
Karen Simon, M.D. has a CMS MIPS Final Score of 84/100 (Quality: 79.4). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is Karen Simon, M.D. located? ▼
Karen Simon, M.D. is located at 2241 WANKEL WAY, Oxnard, CA, 93030. Phone: (805) 983-0521.
What is Karen Simon, M.D.'s NPI number? ▼
Karen Simon, M.D.'s National Provider Identifier (NPI) is 1548384167, issued on 03/19/2007.
Does Karen Simon, M.D. prescribe more brand-name or generic drugs? ▼
Karen Simon, M.D.'s prescribing is 21% brand-name and 79% generic drugs by claim count, with $344K in brand drug costs.
How many Gastroenterology Physician providers are there in the US? ▼
There are 16,601 Gastroenterology Physician providers across 54 states in the US. The average Gastroenterology Physician provider writes 833 Medicare Part D claims per year.
What drugs does Karen Simon, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Karen Simon, M.D.'s most frequently prescribed drugs include Pantoprazole Sodium, Omeprazole, Dexlansoprazole Dr. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Karen Simon, M.D. accept Medicare? ▼
Karen Simon, M.D. appears in CMS Medicare data with 696 Part D claims and 176 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Karen Simon, M.D.'s credentials? ▼
Karen Simon, M.D.'s NPI is 1548384167 with credentials M.D.. 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
View source datasets and methodology notes
- 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.
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.