2026 NPPES data Cardiovascular Disease Physician NPI 1588616585 MD
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PATRICK FENNER, MD

Cardiovascular Disease Physician in DOWNERS GROVE, 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
4K
Medicare Part D claims · 467 beneficiaries · Cardiovascular Disease Physician avg: 3K
Generic prescribing
93%
generic claims · 7% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

PATRICK FENNER, MD filed 4,266 Medicare Part D claims in 2023 as a Cardiovascular Disease Physician in DOWNERS GROVE, Illinois, prescribing 93% generic.

4K
Part D claims, 2023
93%
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.

PATRICK FENNER, MD's Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

4,266 Top 8% higher than 92% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). Below this entry. 400–600: 90,619 prescribers (7%). Below this entry. 600–800: 56,224 prescribers (4%). Below this entry. 800–1,000: 40,919 prescribers (3%). Below this entry. 1,000–1,200: 31,827 prescribers (2%). Below this entry. 1,200–1,400: 26,224 prescribers (2%). Below this entry. 1,400–1,600: 21,710 prescribers (2%). Below this entry. 1,600–1,800: 19,072 prescribers (1%). Below this entry. 1,800–2,000: 16,451 prescribers (1%). Below this entry. 2,000–2,200: 213,991 prescribers (16%). This entry sits in this band. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

Each bar is a band; taller bars hold more prescribers. 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 Medicare Part D Prescriber Public Use File · 2023

Board certification likely (heuristic — not verified)

PATRICK FENNER, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 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 PATRICK FENNER, MD?

Quality data not reported

NPI registry status

Active

Issued 05/17/2006

NPI 1588616585

Primary specialty

Cardiovascular Disease Physician

Mid-sized

24,795 US NPIs in this specialty

Medicare Part D claims

4,266 41% vs specialty avg

2023 prescription claims

Specialty avg: 3,033

Specialty distribution in Illinois

How Cardiovascular Disease Physician compares to other specialties among Illinois providers

Illinois providers

Cardiovascular Disease Physician share within Illinois

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

Specialty board-certification context

Estimated specialty board-certified rate — Cardiovascular Disease Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Cardiovascular Disease Physician ABMS/AOA estimate

Est. board-certified rate (Cardiovascular Disease Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Cardiovascular Disease Physician) — ABMS / AOA estimate

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).

PATRICK FENNER, MD appears in the CMS NPPES registry as a Cardiovascular Disease Physician provider holding MD credentials at 3825 HIGHLAND AVE, DOWNERS GROVE, IL, 60515, with a listed phone of (630) 719-4799. NPI 1588616585 was issued on 05/17/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what FENNER 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 4,266 prescription claims written by this provider, covering 467 Medicare beneficiaries and totaling roughly $415K in drug spend, split 7% brand-name and 93% 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.

Cardiovascular Disease Physician is a mid-sized specialty nationwide, with 24,795 enrolled providers across 54 states and an average of 3,033 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

3825 HIGHLAND AVE
DOWNERS GROVE, IL 60515

Provider Details

NPI 1588616585
Specialty Cardiovascular Disease Physician
Credentials MD
Gender Male
NPI Issued 05/17/2006

Hospital and facility affiliations

Facilities where PATRICK FENNER, 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.

ADVOCATE HEALTH AND HOSPITALS CORPORATION
NAPERVILLE, IL
SWEDISHAMERICAN HOSPITAL
ROCKFORD, 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).

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 PATRICK FENNER, MD. To verify PATRICK FENNER, MD'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 · Generic-heavy

PATRICK FENNER, MD — brand share 7.0%
Specialty average (est.)

7% brand-name claims vs 93% generic, on 4,266 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.

4,266
Total Claims
$415K
Total Drug Cost
467
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
11,741
Total Day Supply
350,808
Brand vs Generic
7% brand / 93% generic
Brand Drug Cost
$336K
Generic Drug Cost
$79K

Patient Demographics

Average Patient Age
75.8 years
Avg HCC Risk Score
1.26
Gender Split
38% female / 62% male
Age Distribution
<65: 14, 65-74: 210, 75-84: 174, 85+: 69

Top Prescribed Drugs (Medicare Part D)

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

What PATRICK FENNER, 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
Atorvastatin Calcium
565
Carvedilol
434
Metoprolol Succinate
317
Lisinopril
254
Rosuvastatin Calcium
214
Metoprolol Tartrate
213
Losartan Potassium
187
Amlodipine Besylate
185
Eliquis
Apixaban
168
Hydrochlorothiazide
165

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

Cardiovascular Disease Physician Overview

How PATRICK FENNER, MD fits within the Cardiovascular Disease Physician landscape nationally.

24,795
Cardiovascular Disease Physician Providers in US
54
States with Cardiovascular Disease Physician
3,033
Avg Claims per Provider

PATRICK FENNER, MD's 4,266 claims are above the specialty average of 3,033.

Nearby Cardiovascular Disease Physician Providers in Illinois

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

Compare Cardiovascular Disease Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is PATRICK FENNER, MD's specialty?
PATRICK FENNER, MD specializes in Cardiovascular Disease Physician and practices in DOWNERS GROVE, Illinois. Credentials: MD.
How much does PATRICK FENNER, MD prescribe under Medicare Part D?
In 2023, PATRICK FENNER, MD wrote 4,266 Medicare Part D claims totaling $415K in drug costs for 467 beneficiaries.
Where is PATRICK FENNER, MD located?
PATRICK FENNER, MD is located at 3825 HIGHLAND AVE, DOWNERS GROVE, IL, 60515. Phone: (630) 719-4799.
What is PATRICK FENNER, MD's NPI number?
PATRICK FENNER, MD's National Provider Identifier (NPI) is 1588616585, issued on 05/17/2006.
Does PATRICK FENNER, MD prescribe more brand-name or generic drugs?
PATRICK FENNER, MD's prescribing is 7% brand-name and 93% generic drugs by claim count, with $336K in brand drug costs.
How many Cardiovascular Disease Physician providers are there in the US?
There are 24,795 Cardiovascular Disease Physician providers across 54 states in the US. The average Cardiovascular Disease Physician provider writes 3,033 Medicare Part D claims per year.
What drugs does PATRICK FENNER, MD prescribe most often?
Based on 2023 Medicare Part D data, PATRICK FENNER, MD's most frequently prescribed drugs include Atorvastatin Calcium, Carvedilol, Metoprolol Succinate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does PATRICK FENNER, MD accept Medicare?
PATRICK FENNER, MD appears in CMS Medicare data with 4,266 Part D claims and 467 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify PATRICK FENNER, MD's credentials?
PATRICK FENNER, MD's NPI is 1588616585 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.
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