NPI registry status
Active
2026 NPPES data Nephrology Physician NPI 1184995094 M.D.
Verify on CMS → Matthew Kaptein, M.D.
Nephrology Physician in Loma Linda, 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 10,569 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
643
Medicare Part D claims · 121 beneficiaries · Nephrology Physician avg: 1K
MIPS score
85.2/100
▲ 2 pts above national avg 83.1 · Above neutral
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Matthew Kaptein, M.D. reported a CMS MIPS final score of 85.2/100 - above the 83.1 national average - and filed 643 Medicare Part D claims in 2023.
- 85.2/100
- MIPS score · +2 vs avg
- 643
- 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.
Matthew Kaptein, 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
85 49th percentile higher than 49% 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 Matthew Kaptein, M.D. 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, Matthew Kaptein, M.D. writes more Part D claims than 31% of them and scores higher on MIPS quality than 58% - placing this provider in the lower-volume, high-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 Matthew Kaptein, M.D.. Source: CMS Medicare Part D Prescriber data and the CMS Merit-based Incentive Payment System, 2023.
✓
Board certification likely (heuristic, not verified)
Matthew Kaptein, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 2 hospital affiliations - 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 Matthew Kaptein, M.D.?
High performer (top quartile)Primary specialty
Nephrology Physician
Medicare Part D claims
643 56% vs specialty avg
MIPS final score
85.2/100 2.1 pts vs avg
Specialty distribution in California
How Nephrology Physician compares to other specialties among California providers
Medicare quality performance, MIPS
Matthew Kaptein, M.D.'s 2023 MIPS final score plotted against the Nephrology Physician national average
- MIPS Final Score
- 85.2/100
- vs 83.1 national avg · 2023 performance year
MIPS final score (Nephrology Physician) - 85.2/100 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).
Matthew Kaptein, M.D. appears in the CMS NPPES registry as a Nephrology Physician provider holding M.D. credentials at 11234 ANDERSON ST, Loma Linda, CA, 92354, with a listed phone of (909) 558-4906. NPI 1184995094 was issued on 01/24/2012.
Medicare Part D records for calendar year 2023 show 643 prescription claims written by this provider, covering 121 Medicare beneficiaries and totaling roughly $148K in drug spend. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 85.2/100 for the 2023 performance year (Quality 71.8, Cost 64.5), compared with the national average of 83.1.
Nephrology Physician is a mid-sized specialty nationwide, with 10,569 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 | 1184995094 |
|---|---|
| Specialty | Nephrology Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 01/24/2012 |
CMS Quality Score (MIPS)
Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.
85.186
Final Score
Avg: 83.1
71.8166
Quality
64.5435
Cost
82
Promoting Interoperability
Reporting: Group practice
Hospital and facility affiliations
Facilities where Matthew Kaptein, 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.
Faculty Physicians And Surgeons OF Llusm
Loma Linda, CA
Sac Health System
San Bernardino, 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).
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 Matthew Kaptein, M.D.. To verify Matthew Kaptein, 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.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
643
Total Claims
$148K
Total Drug Cost
121
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,298
- Total Day Supply
- 37,611
- Generic Drug Cost
- $31K
- Antibiotic Claims
- 23
Patient Demographics
- Average Patient Age
- 68.0 years
- Avg HCC Risk Score
- 4.26
- Gender Split
- 55% female / 45% male
- Age Distribution
- <65: 36, 65-74: 41, 75-84: 29, 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 Matthew Kaptein, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Carvedilol
Carvedilol
61 claims
- Amlodipine Besylate
Amlodipine Besylate
54 claims
- Calcitriol
Calcitriol
54 claims
- Aranesp
Aranesp
45 claims
- Losartan Potassium
Losartan Potassium
45 claims
- Lisinopril
Lisinopril
33 claims
- Furosemide
Furosemide
28 claims
- Nifedipine Er 20
Nifedipine Er
20 claims
| Drug | Claims |
|---|---|
| Carvedilol | 61 |
| Amlodipine Besylate | 54 |
| Calcitriol | 54 |
| Aranesp Darbepoetin Alfa In Polysorbat | 45 |
| Losartan Potassium | 45 |
| Lisinopril | 33 |
| Furosemide | 28 |
| Nifedipine Er Nifedipine | 20 |
| Allopurinol | 15 |
| Spironolactone | 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 Matthew Kaptein, M.D. fits within the Nephrology Physician landscape nationally.
10,569
Nephrology Physician Providers in US
55
States with Nephrology Physician
1,454
Avg Claims per Provider
Matthew Kaptein, M.D.'s 643 claims are below the specialty average of 1,454.
Nearby Nephrology Physician Providers in California
Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as Kaptein.
Dr. Antoine Abcar
MD
Los Angeles, CA
Dr. Basmah Abdalla
M.D.
Los Angeles, CA
Dr. Omaran Abdeen
M.D.
Mission Hills, CA
Dr. Anas Abou-Ismail
MD
Palm Springs, CA
Dr. Sreedhar Adapa
M.D.
Visalia, CA
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 California 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.
Healthcare Guides
Learn more about finding, verifying, and understanding healthcare providers.
How to Find a Doctor
Step-by-step guide to choosing a provider
Verify Credentials
Check NPI, board certification & license status
Medical Specialties Explained
Who treats what and how specialties differ
Understanding Medicare Claims Data
What prescribing data reveals about a provider
In-Network vs Out-of-Network
How insurance networks affect your costs
Telehealth Guide
Virtual care options and coverage in 2026
Explore California
Frequently Asked Questions
What is Matthew Kaptein, M.D.'s specialty? ▼
Matthew Kaptein, M.D. specializes in Nephrology Physician and practices in Loma Linda, California. Credentials: M.D..
How much does Matthew Kaptein, M.D. prescribe under Medicare Part D? ▼
In 2023, Matthew Kaptein, M.D. wrote 643 Medicare Part D claims totaling $148K in drug costs for 121 beneficiaries.
What is Matthew Kaptein, M.D.'s Medicare quality score? ▼
Matthew Kaptein, M.D. has a CMS MIPS Final Score of 85.2/100 (Quality: 71.8, Cost: 64.5). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is Matthew Kaptein, M.D. located? ▼
Matthew Kaptein, M.D. is located at 11234 ANDERSON ST, Loma Linda, CA, 92354. Phone: (909) 558-4906.
What is Matthew Kaptein, M.D.'s NPI number? ▼
Matthew Kaptein, M.D.'s National Provider Identifier (NPI) is 1184995094, issued on 01/24/2012.
How many Nephrology Physician providers are there in the US? ▼
There are 10,569 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 Matthew Kaptein, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Matthew Kaptein, M.D.'s most frequently prescribed drugs include Carvedilol, Amlodipine Besylate, Calcitriol. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Matthew Kaptein, M.D. accept Medicare? ▼
Matthew Kaptein, M.D. appears in CMS Medicare data with 643 Part D claims and 121 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Matthew Kaptein, M.D.'s credentials? ▼
Matthew Kaptein, M.D.'s NPI is 1184995094 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.