NPI registry status
Active
2026 NPPES data Internal Medicine Physician NPI 1659489060 DO
Verify on CMS → Herbert Brennan, DO
Internal Medicine Physician in East Greenwich, Rhode Island.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 172,858 in Internal Medicine 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
7K
Medicare Part D claims · 498 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
90%
generic claims · 9% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$154.89
2 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Herbert Brennan, DO filed 6,901 Medicare Part D claims in 2023 as a Internal Medicine Physician in East Greenwich, Rhode Island, prescribing 90% generic.
- 7K
- Part D claims, 2023
- 90%
- generic prescribing
- $154.89
- industry payments (Sunshine Act)
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.
Herbert Brennan, DO's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
6,901 Top 4% higher than 96% of 1,370,886 prescribers
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-eligible specialty (heuristic, not verified)
Herbert Brennan, DO practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Herbert Brennan, DO?
Quality data not reportedPrimary specialty
Internal Medicine Physician
Medicare Part D claims
6,901 154% vs specialty avg
Specialty distribution in Rhode Island
How Internal Medicine Physician compares to other specialties among Rhode Island providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Internal Medicine Physician. Verify directly:
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).
Herbert Brennan, DO appears in the CMS NPPES registry as a Internal Medicine Physician provider holding DO credentials at 2358 SOUTH COUNTY TRAIL, East Greenwich, RI, 02818, with a listed phone of (401) 886-6000. NPI 1659489060 was issued on 08/26/2006.
Medicare Part D records for calendar year 2023 show 6,901 prescription claims written by this provider, covering 498 Medicare beneficiaries and totaling roughly $441K in drug spend, split 9% brand-name and 90% generic by claim count, with an opioid prescribing rate of 3.5%.
Internal Medicine Physician is a high-volume specialty nationwide, with 172,858 enrolled providers across 56 states and an average of 2,716 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 | 1659489060 |
|---|---|
| Specialty | Internal Medicine Physician |
| Credentials | DO |
| Gender | Male |
| NPI Issued | 08/26/2006 |
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 Herbert Brennan, DO. Source: openpaymentsdata.cms.gov.
Total received
$155
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 · Generic-heavy
Herbert Brennan, DO - brand share 9.0%
Internal Medicine Physician average
9% brand-name claims vs 90% generic, on 6,901 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.
6,901
Total Claims
$441K
Total Drug Cost
498
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 15,052
- Total Day Supply
- 440,459
- Brand vs Generic
- 9% brand / 90% generic
- Brand Drug Cost
- $311K
- Generic Drug Cost
- $126K
- Opioid Claims
- 243 (3.5% rate)
- Antibiotic Claims
- 168
Patient Demographics
- Average Patient Age
- 75.2 years
- Avg HCC Risk Score
- 1.01
- Gender Split
- 47% female / 53% male
- Age Distribution
- <65: 22, 65-74: 235, 75-84: 169, 85+: 72
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Herbert Brennan, DO prescribes most
Top Medicare Part D drugs by claim count, 2023
- Simvastatin
Simvastatin
293 claims
- Levothyroxine Sodium
Levothyroxine Sodium
280 claims
- Atorvastatin Calcium
Atorvastatin Calcium
277 claims
- Omeprazole
Omeprazole
265 claims
- Amlodipine Besylate
Amlodipine Besylate
263 claims
- Lisinopril
Lisinopril
261 claims
- Clonazepam
Clonazepam
222 claims
- Sertraline Hcl
Sertraline Hcl
214 claims
| Drug | Claims |
|---|---|
| Simvastatin | 293 |
| Levothyroxine Sodium | 280 |
| Atorvastatin Calcium | 277 |
| Omeprazole | 265 |
| Amlodipine Besylate | 263 |
| Lisinopril | 261 |
| Clonazepam | 222 |
| Sertraline Hcl | 214 |
| Metoprolol Tartrate | 182 |
| Metformin Hcl | 156 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Internal Medicine Physician Overview
How Herbert Brennan, DO fits within the Internal Medicine Physician landscape nationally.
172,858
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider
Herbert Brennan, DO's 6,901 claims are above the specialty average of 2,716.
Nearby Internal Medicine Physician Providers in Rhode Island
Other clinicians with the same primary specialty enrolled in Rhode Island, drawn from the same CMS NPPES roster as Brennan.
Dr. Salvatore Abbruzzese
D.O. PC
Wakefield, RI
Dr. Thaer Abdelfattah
M.D.
Providence, RI
Dr. Azamat Abdyraimov
MD
Providence, RI
Dr. Marie Abejuela
MD
Providence, RI
Dr. Joanna Abi Chebl
MD
Providence, RI
Compare Internal Medicine 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 Rhode Island medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Internal Medicine 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
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Medical Specialties Explained
Who treats what and how specialties differ
Understanding Medicare Claims Data
What prescribing data reveals about a provider
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How insurance networks affect your costs
Telehealth Guide
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Explore Rhode Island
Frequently Asked Questions
What is Herbert Brennan, DO's specialty? ▼
Herbert Brennan, DO specializes in Internal Medicine Physician and practices in East Greenwich, Rhode Island. Credentials: DO.
How much does Herbert Brennan, DO prescribe under Medicare Part D? ▼
In 2023, Herbert Brennan, DO wrote 6,901 Medicare Part D claims totaling $441K in drug costs for 498 beneficiaries.
Where is Herbert Brennan, DO located? ▼
Herbert Brennan, DO is located at 2358 SOUTH COUNTY TRAIL, East Greenwich, RI, 02818. Phone: (401) 886-6000.
What is Herbert Brennan, DO's NPI number? ▼
Herbert Brennan, DO's National Provider Identifier (NPI) is 1659489060, issued on 08/26/2006.
Does Herbert Brennan, DO prescribe more brand-name or generic drugs? ▼
Herbert Brennan, DO's prescribing is 9% brand-name and 90% generic drugs by claim count, with $311K in brand drug costs.
Does Herbert Brennan, DO prescribe opioids? ▼
Yes, Herbert Brennan, DO had 243 opioid claims in 2023 with an opioid prescribing rate of 3.5%.
How many Internal Medicine Physician providers are there in the US? ▼
There are 172,858 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does Herbert Brennan, DO prescribe most often? ▼
Based on 2023 Medicare Part D data, Herbert Brennan, DO's most frequently prescribed drugs include Simvastatin, Levothyroxine Sodium, Atorvastatin Calcium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Herbert Brennan, DO accept Medicare? ▼
Herbert Brennan, DO appears in CMS Medicare data with 6,901 Part D claims and 498 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Herbert Brennan, DO's credentials? ▼
Herbert Brennan, DO's NPI is 1659489060 with credentials DO. 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.
- 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.