2026 NPPES data Clinical Cardiac Electrophysiology Physician NPI 1538336177 MD
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ROBERT DRENNAN, MD

Clinical Cardiac Electrophysiology Physician in BATON ROUGE, Louisiana. 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
3K
Medicare Part D claims · 372 beneficiaries · Clinical Cardiac Electrophysiology Physician avg: 2K
Generic prescribing
81%
generic claims · 19% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$5.1K
80 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

ROBERT DRENNAN, MD filed 3,179 Medicare Part D claims in 2023 as a Clinical Cardiac Electrophysiology Physician in BATON ROUGE, Louisiana, prescribing 81% generic.

3K
Part D claims, 2023
81%
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.

ROBERT DRENNAN, MD's Medicare Part D volume vs every U.S. prescriber

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

3,179 Top 11% higher than 89% 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)

ROBERT DRENNAN, 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 ROBERT DRENNAN, MD?

Quality data not reported

NPI registry status

Active

Issued 05/13/2008

NPI 1538336177

Primary specialty

Clinical Cardiac Electrophysiology Physician

Niche

1,570 US NPIs in this specialty

Medicare Part D claims

3,179 99% vs specialty avg

2023 prescription claims

Specialty avg: 1,596

Specialty distribution in Louisiana

How Clinical Cardiac Electrophysiology Physician compares to other specialties among Louisiana providers

Louisiana providers

Clinical Cardiac Electrophysiology Physician share within Louisiana

1. Clinical Cardiac Electrophysiology Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Clinical Cardiac Electrophysiology Physician share within Louisiana

Specialty board-certification context

Estimated specialty board-certified rate — Clinical Cardiac Electrophysiology Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Clinical Cardiac Electrophysiology Physician ABMS/AOA estimate

Est. board-certified rate (Clinical Cardiac Electrophysiology Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Clinical Cardiac Electrophysiology 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).

ROBERT DRENNAN, MD appears in the CMS NPPES registry as a Clinical Cardiac Electrophysiology Physician provider holding MD credentials at 8401 PICARDY AVE, BATON ROUGE, LA, 70809, with a listed phone of (225) 308-0247. NPI 1538336177 was issued on 05/13/2008. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what DRENNAN 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 3,179 prescription claims written by this provider, covering 372 Medicare beneficiaries and totaling roughly $633K in drug spend, split 19% brand-name and 81% generic by claim count, with an opioid prescribing rate of 1.3%. 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.

Clinical Cardiac Electrophysiology Physician is a narrow specialty nationwide, with 1,570 enrolled providers across 52 states and an average of 1,596 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

8401 PICARDY AVE
BATON ROUGE, LA 70809

Provider Details

NPI 1538336177
Specialty Clinical Cardiac Electrophysiology Physician
Credentials MD
Gender Male
NPI Issued 05/13/2008

Hospital and facility affiliations

Facilities where ROBERT DRENNAN, 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.

CARDIOVASCULAR INSTITUTE OF THE SOUTH, LLC
BATON ROUGE, LA
HOSPITAL SERVICE DISTRICT 1 OF EAST BATON ROUGE PARISH
ZACHARY, LA

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 ROBERT DRENNAN, MD. Source: openpaymentsdata.cms.gov.

Total received

$5.1K

Largest payer

Abbott Laboratories

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

ROBERT DRENNAN, MD — brand share 19.0%
Specialty average (est.)

19% brand-name claims vs 81% generic, on 3,179 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.

3,179
Total Claims
$633K
Total Drug Cost
372
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
6,955
Total Day Supply
204,719
Brand vs Generic
19% brand / 81% generic
Brand Drug Cost
$578K
Generic Drug Cost
$55K
Opioid Claims
41 (1.3% rate)
Antibiotic Claims
36

Patient Demographics

Average Patient Age
71.5 years
Avg HCC Risk Score
1.97
Gender Split
50% female / 50% male
Age Distribution
<65: 47, 65-74: 200, 75-84: 108, 85+: 17

Top Prescribed Drugs (Medicare Part D)

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

What ROBERT DRENNAN, 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
Eliquis
Apixaban
345
Metoprolol Succinate
244
Atorvastatin Calcium
165
Rosuvastatin Calcium
154
Amlodipine Besylate
151
Furosemide
144
Amiodarone Hcl
135
Sotalol
Sotalol Hcl
126
Entresto
Sacubitril/Valsartan
125
Metoprolol Tartrate
119

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

Clinical Cardiac Electrophysiology Physician Overview

How ROBERT DRENNAN, MD fits within the Clinical Cardiac Electrophysiology Physician landscape nationally.

1,570
Clinical Cardiac Electrophysiology Physician Providers in US
52
States with Clinical Cardiac Electrophysiology Physician
1,596
Avg Claims per Provider

ROBERT DRENNAN, MD's 3,179 claims are above the specialty average of 1,596.

Nearby Clinical Cardiac Electrophysiology Physician Providers in Louisiana

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

Compare Clinical Cardiac Electrophysiology Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is ROBERT DRENNAN, MD's specialty?
ROBERT DRENNAN, MD specializes in Clinical Cardiac Electrophysiology Physician and practices in BATON ROUGE, Louisiana. Credentials: MD.
How much does ROBERT DRENNAN, MD prescribe under Medicare Part D?
In 2023, ROBERT DRENNAN, MD wrote 3,179 Medicare Part D claims totaling $633K in drug costs for 372 beneficiaries.
Where is ROBERT DRENNAN, MD located?
ROBERT DRENNAN, MD is located at 8401 PICARDY AVE, BATON ROUGE, LA, 70809. Phone: (225) 308-0247.
What is ROBERT DRENNAN, MD's NPI number?
ROBERT DRENNAN, MD's National Provider Identifier (NPI) is 1538336177, issued on 05/13/2008.
Does ROBERT DRENNAN, MD prescribe more brand-name or generic drugs?
ROBERT DRENNAN, MD's prescribing is 19% brand-name and 81% generic drugs by claim count, with $578K in brand drug costs.
Does ROBERT DRENNAN, MD prescribe opioids?
Yes, ROBERT DRENNAN, MD had 41 opioid claims in 2023 with an opioid prescribing rate of 1.3%.
How many Clinical Cardiac Electrophysiology Physician providers are there in the US?
There are 1,570 Clinical Cardiac Electrophysiology Physician providers across 52 states in the US. The average Clinical Cardiac Electrophysiology Physician provider writes 1,596 Medicare Part D claims per year.
What drugs does ROBERT DRENNAN, MD prescribe most often?
Based on 2023 Medicare Part D data, ROBERT DRENNAN, MD's most frequently prescribed drugs include Eliquis, Metoprolol Succinate, Atorvastatin Calcium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does ROBERT DRENNAN, MD accept Medicare?
ROBERT DRENNAN, MD appears in CMS Medicare data with 3,179 Part D claims and 372 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify ROBERT DRENNAN, MD's credentials?
ROBERT DRENNAN, MD's NPI is 1538336177 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