NPI registry status
Active
2026 NPPES data Internal Medicine Physician NPI 1093219701 MD
Verify on CMS → John Marston, MD
Internal Medicine Physician in Baton Rouge, Louisiana. 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
2K
Medicare Part D claims · 524 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
84%
generic claims · 15% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$14.26
1 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
John Marston, MD filed 2,230 Medicare Part D claims in 2023 as a Internal Medicine Physician in Baton Rouge, Louisiana, prescribing 84% generic.
- 2K
- Part D claims, 2023
- 84%
- 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.
John Marston, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
2,230 Top 15% higher than 85% 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 certification likely (heuristic, not verified)
John Marston, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation - 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 John Marston, MD?
Quality data not reportedPrimary specialty
Internal Medicine Physician
Medicare Part D claims
2,230 18% vs specialty avg
Specialty distribution in Louisiana
How Internal Medicine Physician compares to other specialties among Louisiana 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:
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).
John Marston, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 5246 BRITTANY DR, Baton Rouge, LA, 70808, with a listed phone of (225) 757-4070. NPI 1093219701 was issued on 03/19/2018. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Marston 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 2,230 prescription claims written by this provider, covering 524 Medicare beneficiaries and totaling roughly $215K in drug spend, split 15% brand-name and 84% generic by claim count, with an opioid prescribing rate of 0.8%. 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.
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 | 1093219701 |
|---|---|
| Specialty | Internal Medicine Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 03/19/2018 |
Hospital and facility affiliations
Facilities where John Marston, 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.
Baton Rouge Clinic, A Medical Corporation
Baton Rouge, 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 John Marston, MD. Source: openpaymentsdata.cms.gov.
Total received
$14
Largest payer
Supernus Pharmaceuticals, 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
John Marston, MD - brand share 15.0%
Internal Medicine Physician average
15% brand-name claims vs 84% generic, on 2,230 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.
2,230
Total Claims
$215K
Total Drug Cost
524
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 3,763
- Total Day Supply
- 101,066
- Brand vs Generic
- 15% brand / 84% generic
- Brand Drug Cost
- $189K
- Generic Drug Cost
- $25K
- Opioid Claims
- 18 (0.8% rate)
- Antibiotic Claims
- 182
Patient Demographics
- Average Patient Age
- 73.2 years
- Avg HCC Risk Score
- 1.31
- Gender Split
- 56% female / 44% male
- Age Distribution
- <65: 51, 65-74: 241, 75-84: 179, 85+: 53
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What John Marston, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Atorvastatin Calcium
Atorvastatin Calcium
92 claims
- Amlodipine Besylate
Amlodipine Besylate
82 claims
- Ipratropium Bromide
Ipratropium Bromide
79 claims
- Doxycycline Hyclate
Doxycycline Hyclate
69 claims
- Levothyroxine Sodium
Levothyroxine Sodium
65 claims
- Meloxicam
Meloxicam
55 claims
- Duloxetine Hcl
Duloxetine Hcl
50 claims
- Gabapentin
Gabapentin
50 claims
| Drug | Claims |
|---|---|
| Atorvastatin Calcium | 92 |
| Amlodipine Besylate | 82 |
| Ipratropium Bromide | 79 |
| Doxycycline Hyclate | 69 |
| Levothyroxine Sodium | 65 |
| Meloxicam | 55 |
| Duloxetine Hcl | 50 |
| Gabapentin | 50 |
| Hydrochlorothiazide | 46 |
| Fluticasone Propionate | 44 |
* 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 John Marston, MD 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
John Marston, MD's 2,230 claims are below the specialty average of 2,716.
Nearby Internal Medicine Physician Providers in Louisiana
Other clinicians with the same primary specialty enrolled in Louisiana, drawn from the same CMS NPPES roster as Marston.
Dr. Alfred Abaunza
M.D.
New Orleans, LA
Mokhtar Abdallah
Baton Rouge, LA
Dr. David Abdehou
MD
Shreveport, LA
Dr. Mazin Abdelghany
MD
Covington, LA
Dr. Youssef Abdelmalek
M.D
Alexandria, LA
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 Louisiana 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
Learn more about finding, verifying, and understanding healthcare providers.
How to Find a Doctor
Step-by-step guide to choosing a provider
Verify Credentials
Check NPI, board certification & license status
Medical Specialties Explained
Who treats what and how specialties differ
Understanding Medicare Claims Data
What prescribing data reveals about a provider
In-Network vs Out-of-Network
How insurance networks affect your costs
Telehealth Guide
Virtual care options and coverage in 2026
Explore Louisiana
Frequently Asked Questions
What is John Marston, MD's specialty? ▼
John Marston, MD specializes in Internal Medicine Physician and practices in Baton Rouge, Louisiana. Credentials: MD.
How much does John Marston, MD prescribe under Medicare Part D? ▼
In 2023, John Marston, MD wrote 2,230 Medicare Part D claims totaling $215K in drug costs for 524 beneficiaries.
Where is John Marston, MD located? ▼
John Marston, MD is located at 5246 BRITTANY DR, Baton Rouge, LA, 70808. Phone: (225) 757-4070.
What is John Marston, MD's NPI number? ▼
John Marston, MD's National Provider Identifier (NPI) is 1093219701, issued on 03/19/2018.
Does John Marston, MD prescribe more brand-name or generic drugs? ▼
John Marston, MD's prescribing is 15% brand-name and 84% generic drugs by claim count, with $189K in brand drug costs.
Does John Marston, MD prescribe opioids? ▼
Yes, John Marston, MD had 18 opioid claims in 2023 with an opioid prescribing rate of 0.8%.
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 John Marston, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, John Marston, MD's most frequently prescribed drugs include Atorvastatin Calcium, Amlodipine Besylate, Ipratropium Bromide. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does John Marston, MD accept Medicare? ▼
John Marston, MD appears in CMS Medicare data with 2,230 Part D claims and 524 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify John Marston, MD's credentials? ▼
John Marston, MD's NPI is 1093219701 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
Compiled from official public sources by the PlainDoctor editorial team.