2026 NPPES data Interventional Cardiology Physician NPI 1063660074 P.A.
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NATHANIEL CLARK, P.A.

Interventional Cardiology Physician in CARBONDALE, Illinois. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
Prescribing volume
1K
Medicare Part D claims · 323 beneficiaries · Interventional Cardiology Physician avg: 3K
Generic prescribing
79%
generic claims · 21% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
73.8843/100
▼ 9 pts below national avg 83.1 · [object Object]
Industry payments
$2.0K
94 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: NATHANIEL CLARK, P.A. is a Interventional Cardiology Physician ([object Object]) practicing in CARBONDALE, Illinois with a Medicare Part D prescribing footprint of 1K claims across 323 beneficiaries — 21% brand-name prescribing . Their CMS MIPS Final Score of 73.8843/100 (national average: 83.1) reflects performance across Quality, Cost, Interoperability, and Improvement Activities . Industry payments of $2.0K across 94 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: NATHANIEL CLARK, P.A. reported a CMS MIPS final score of 73.8843 out of 100, below the 83.1 national average, and filed 1,269 Medicare Part D claims in 2023. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board certification likely (heuristic — not verified)

NATHANIEL CLARK, P.A. 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).

NATHANIEL CLARK, P.A. at a glance

Below national average

NPI registry status

Active

Issued 09/03/2008

NPI 1063660074

Primary specialty

Interventional Cardiology Physician

Niche

3,382 US NPIs in this specialty

Medicare Part D claims

1,269 57% vs specialty avg

2023 prescription claims

Specialty avg: 2,984

MIPS final score

73.8843/100 9.215699999999998% pts

Mid-tier band

vs 83.1 national avg

Specialty distribution in Illinois

How Interventional Cardiology Physician compares to other specialties among Illinois providers

Illinois providers

Interventional Cardiology Physician share within Illinois

1. Interventional Cardiology Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Interventional Cardiology Physician share within Illinois

Medicare quality performance — MIPS

NATHANIEL CLARK, P.A.'s 2023 MIPS final score plotted against the Interventional Cardiology Physician national average

Below national average
MIPS Final Score
73.8843/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Interventional Cardiology Physician) — 73.8843/100 vs national avg 83.1

0%100%National avg83%73.9%
MIPS final score (Interventional Cardiology Physician) — 73.8843/100 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).

NATHANIEL CLARK, P.A. is a Interventional Cardiology Physician provider practicing in CARBONDALE, Illinois, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: P.A.. NPI: 1063660074. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.

NATHANIEL CLARK, P.A. appears in the CMS NPPES registry as a Interventional Cardiology Physician provider holding P.A. credentials at 409 W OAK ST, CARBONDALE, IL, 62901, with a listed phone of (618) 529-4455. NPI 1063660074 was issued on 09/03/2008. 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 1,269 prescription claims written by this provider, covering 323 Medicare beneficiaries and totaling roughly $265K in drug spend, split 21% brand-name and 79% 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 73.8843/100 for the 2023 performance year (Quality 53.7907, Cost 56.5295), compared with the national average of 83.1.

Interventional Cardiology Physician is a narrow specialty nationwide, with 3,382 enrolled providers across 53 states and an average of 2,984 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

409 W OAK ST
CARBONDALE, IL 62901

Provider Details

NPI 1063660074
Specialty Interventional Cardiology Physician
Credentials P.A.
Gender Male
NPI Issued 09/03/2008

CMS Quality Score (MIPS)

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

73.8843
Final Score
Avg: 83.1
53.7907
Quality
56.5295
Cost
91
Promoting Interoperability

Reporting: Group practice

Hospital and facility affiliations

Facilities where NATHANIEL CLARK, P.A. 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.

DEACONESS ILLINOIS SPECIALTY CLINIC, INC.
HARRISBURG, IL

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 NATHANIEL CLARK, P.A.. Source: openpaymentsdata.cms.gov.

Total received

$2.0K

Largest payer

E.R. Squibb & Sons, L.L.C.

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 — Illinois IDFPR 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 ~42K Illinois medical licensees in 2023 — they are NOT specific to NATHANIEL CLARK, P.A.. To verify NATHANIEL CLARK, P.A.'s current license status, search the IDFPR public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

106
Total board actions, Illinois 2023
Across 103 cases
2.52
Actions per 1,000 licensees
Illinois statewide rate
probation
Most common action type
38 cases

IDFPR 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 Illinois disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Brand vs generic prescribing mix · Typical

NATHANIEL CLARK, P.A. — brand share 21.0%
Specialty average (est.)

21% brand-name claims vs 79% generic, on 1,269 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.

1,269
Total Claims
$265K
Total Drug Cost
323
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
2,329
Total Day Supply
68,394
Brand vs Generic
21% brand / 79% generic
Brand Drug Cost
$234K
Generic Drug Cost
$30K

Patient Demographics

Average Patient Age
71.8 years
Avg HCC Risk Score
1.69
Gender Split
50% female / 50% male
Age Distribution
<65: 61, 65-74: 127, 75-84: 109, 85+: 26

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

Drug Claims
Eliquis
Apixaban
111
Carvedilol
91
Metoprolol Succinate
89
Furosemide
71
Atorvastatin Calcium
58
Isosorbide Mononitrate Er
Isosorbide Mononitrate
57
Amiodarone Hcl
53
Amlodipine Besylate
53
Rosuvastatin Calcium
47
Metoprolol Tartrate
45

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Interventional Cardiology Physician Overview

How NATHANIEL CLARK, P.A. fits within the Interventional Cardiology Physician landscape nationally.

3,382
Interventional Cardiology Physician Providers in US
53
States with Interventional Cardiology Physician
2,984
Avg Claims per Provider

NATHANIEL CLARK, P.A.'s 1,269 claims are below the specialty average of 2,984.

Nearby Interventional Cardiology Physician Providers in Illinois

Other clinicians with the same primary specialty enrolled in Illinois, drawn from the same CMS NPPES roster as CLARK.

Compare Interventional Cardiology Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is NATHANIEL CLARK, P.A.'s specialty?
NATHANIEL CLARK, P.A. specializes in Interventional Cardiology Physician and practices in CARBONDALE, Illinois. Credentials: P.A..
How much does NATHANIEL CLARK, P.A. prescribe under Medicare Part D?
In 2023, NATHANIEL CLARK, P.A. wrote 1,269 Medicare Part D claims totaling $265K in drug costs for 323 beneficiaries.
What is NATHANIEL CLARK, P.A.'s Medicare quality score?
NATHANIEL CLARK, P.A. has a CMS MIPS Final Score of 73.8843/100 (Quality: 53.7907, Cost: 56.5295). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is NATHANIEL CLARK, P.A. located?
NATHANIEL CLARK, P.A. is located at 409 W OAK ST, CARBONDALE, IL, 62901. Phone: (618) 529-4455.
What is NATHANIEL CLARK, P.A.'s NPI number?
NATHANIEL CLARK, P.A.'s National Provider Identifier (NPI) is 1063660074, issued on 09/03/2008.
Does NATHANIEL CLARK, P.A. prescribe more brand-name or generic drugs?
NATHANIEL CLARK, P.A.'s prescribing is 21% brand-name and 79% generic drugs by claim count, with $234K in brand drug costs.
How many Interventional Cardiology Physician providers are there in the US?
There are 3,382 Interventional Cardiology Physician providers across 53 states in the US. The average Interventional Cardiology Physician provider writes 2,984 Medicare Part D claims per year.
What drugs does NATHANIEL CLARK, P.A. prescribe most often?
Based on 2023 Medicare Part D data, NATHANIEL CLARK, P.A.'s most frequently prescribed drugs include Eliquis, Carvedilol, Metoprolol Succinate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does NATHANIEL CLARK, P.A. accept Medicare?
NATHANIEL CLARK, P.A. appears in CMS Medicare data with 1,269 Part D claims and 323 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify NATHANIEL CLARK, P.A.'s credentials?
NATHANIEL CLARK, P.A.'s NPI is 1063660074 with credentials P.A.. 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