James Clark, MD
Rheumatology Physician in Phoenix, Arizona. This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 6,181 in Rheumatology 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.
Source: CMS Medicare Part D Prescriber Public Use File, 2023
What the federal data shows
James Clark, MD reported a CMS MIPS final score of 80.5/100 - below the 83.1 national average - and filed 373 Medicare Part D claims in 2023.
- 80.5/100
- MIPS score · -3 vs avg
- 373
- Part D claims, 2023
- 76%
- 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.
James Clark, MD's MIPS score vs every scored U.S. clinician
CMS Merit-based Incentive Payment System (MIPS) final score, 2023, the federal quality measure
81 33rd percentile higher than 33% 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 James Clark, MD sits
This provider among rheumatology physician peers
Across the 2,181 rheumatology physician providers who report both Medicare Part D prescribing and a MIPS quality score, James Clark, MD writes more Part D claims than 9% of them and scores higher on MIPS quality than 38% - 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 rheumatology physician peer from a representative sample of 60; the gold marker is James Clark, MD. Source: CMS Medicare Part D Prescriber data and the CMS Merit-based Incentive Payment System, 2023.
James Clark, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting - 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 James Clark, MD?
Near national averagePrimary specialty
Medicare Part D claims
MIPS final score
Specialty distribution in Arizona
How Rheumatology Physician compares to other specialties among Arizona providers
Largest specialties in Arizona (% of in-state providers)
Rheumatology Physician ranks #125 among Arizona's specialties (0.1% of in-state providers)
Each bar is a specialty's share of the Arizona provider total, by primary NUCC taxonomy. The highlighted bar is Rheumatology Physician; the long tail of smaller specialties is omitted for legibility.
Medicare quality performance, MIPS
James Clark, MD's 2023 MIPS final score plotted against the Rheumatology Physician national average
- MIPS Final Score
- 80.5/100
- vs 83.1 national avg · 2023 performance year
MIPS final score (Rheumatology Physician) - 80.5/100 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 Rheumatology Physician US NPIs
80.5/100 MIPS final score - 2.6 pts below the 83.1 national average
Quality, Cost, Promoting Interoperability, and Improvement Activities composite score for the 2023 performance year. Specialty: Rheumatology Physician. Quality dim: 93.1. Cost dim: 62.6.
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).
James Clark, MD appears in the CMS NPPES registry as a Rheumatology Physician provider holding MD credentials at 5333 N 7TH ST STE B112, Phoenix, AZ, 85014, with a listed phone of (480) 571-6761. NPI 1154954758 was issued on 02/21/2020. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Clark 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 373 prescription claims written by this provider, covering 143 Medicare beneficiaries and totaling roughly $529K in drug spend, split 24% brand-name and 76% generic by claim count. 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 80.5/100 for the 2023 performance year (Quality 93.1, Cost 62.6), compared with the national average of 83.1.
Rheumatology Physician is a mid-sized specialty nationwide, with 6,181 enrolled providers across 52 states and an average of 2,054 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 | 1154954758 |
|---|---|
| Specialty | Rheumatology Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 02/21/2020 |
Verify this provider's license
PlainDoctor pulls this profile from the CMS NPPES public registry. Confirm James Clark, MD's current license status, disciplinary history, and board certifications with the Arizona Medical Board in Arizona 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
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 James Clark, MD. Source: openpaymentsdata.cms.gov.
Total received
$170
Largest payer
Amgen 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.
Brand vs generic prescribing mix · Typical
24% brand-name claims vs 76% generic, on 373 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.
Prescribing Breakdown
- 30-Day Fills
- 655
- Total Day Supply
- 19,187
- Brand vs Generic
- 24% brand / 76% generic
- Brand Drug Cost
- $520K
- Generic Drug Cost
- $9K
Patient Demographics
- Average Patient Age
- 75.5 years
- Avg HCC Risk Score
- 1.41
- Gender Split
- 73% female / 27% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What James Clark, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Prednisone
Prednisone
63 claims
- Hydroxychloroquine…
Hydroxychloroquine Sulfate
53 claims
- Methotrexate
Methotrexate
39 claims
- Allopurinol 21
Allopurinol
21 claims
- Humira(Cf) Pen 19
Humira(Cf) Pen
19 claims
- Duloxetine Hcl 14
Duloxetine Hcl
14 claims
- Azathioprine 13
Azathioprine
13 claims
- Leflunomide 13
Leflunomide
13 claims
| Drug | Claims |
|---|---|
| Prednisone | 63 |
| Hydroxychloroquine Sulfate | 53 |
| Methotrexate Methotrexate Sodium | 39 |
| Allopurinol | 21 |
| Humira(Cf) Pen Adalimumab | 19 |
| Duloxetine Hcl | 14 |
| Azathioprine | 13 |
| Leflunomide | 13 |
| Xeljanz Xr Tofacitinib Citrate | 13 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Rheumatology Physician Overview
How James Clark, MD fits within the Rheumatology Physician landscape nationally.
James Clark, MD's 373 claims are below the specialty average of 2,054.
Nearby Rheumatology Physician Providers in Arizona
Other clinicians with the same primary specialty enrolled in Arizona, drawn from the same CMS NPPES roster as Clark.
Compare Rheumatology 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 Arizona medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Rheumatology 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.
Explore Arizona
Frequently Asked Questions
What is James Clark, MD's specialty? ▼
How much does James Clark, MD prescribe under Medicare Part D? ▼
What is James Clark, MD's Medicare quality score? ▼
Where is James Clark, MD located? ▼
What is James Clark, MD's NPI number? ▼
Does James Clark, MD prescribe more brand-name or generic drugs? ▼
How many Rheumatology Physician providers are there in the US? ▼
What drugs does James Clark, MD prescribe most often? ▼
Does James Clark, MD accept Medicare? ▼
How can I verify James Clark, MD's credentials? ▼
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