2026 NPPES data Geriatric Medicine (Family Medicine) Physician NPI 1083774228 MD
Verify on CMS →

CARLOS MARRERO, MD

Geriatric Medicine (Family Medicine) Physician in SAN JUAN, Puerto Rico. 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
717
Medicare Part D claims · 92 beneficiaries · Geriatric Medicine (Family Medicine) Physician avg: 5K
Generic prescribing
95%
generic claims · 5% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$136.44
3 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: CARLOS MARRERO, MD is a Geriatric Medicine (Family Medicine) Physician ([object Object]) practicing in SAN JUAN, Puerto Rico with a Medicare Part D prescribing footprint of 717 claims across 92 beneficiaries — 5% brand-name prescribing . Industry payments of $136.44 across 3 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: CARLOS MARRERO, MD filed 717 Medicare Part D claims in 2023 across SAN JUAN, Puerto Rico. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board-eligible specialty (heuristic — not verified)

CARLOS MARRERO, MD 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).

CARLOS MARRERO, MD at a glance

Quality data not reported

NPI registry status

Active

Issued 12/11/2006

NPI 1083774228

Primary specialty

Geriatric Medicine (Family Medicine) Physician

Niche

1,779 US NPIs in this specialty

Medicare Part D claims

717 85% vs specialty avg

2023 prescription claims

Specialty avg: 4,854

Specialty distribution in Puerto Rico

How Geriatric Medicine (Family Medicine) Physician compares to other specialties among Puerto Rico providers

Puerto Rico providers

Geriatric Medicine (Family Medicine) Physician share within Puerto Rico

1. Geriatric Medicine (Family Medicine) Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Geriatric Medicine (Family Medicine) Physician share within Puerto Rico

Specialty board-certification context

Estimated specialty board-certified rate — Geriatric Medicine (Family Medicine) Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Geriatric Medicine (Family Medicine) Physician ABMS/AOA estimate

Est. board-certified rate (Geriatric Medicine (Family Medicine) Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Geriatric Medicine (Family Medicine) 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).

CARLOS MARRERO, MD is a Geriatric Medicine (Family Medicine) Physician provider practicing in SAN JUAN, Puerto Rico, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1083774228. 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.

CARLOS MARRERO, MD appears in the CMS NPPES registry as a Geriatric Medicine (Family Medicine) Physician provider holding MD credentials at CESAR GONZALEZ #463 URB ROOSEVELT, SAN JUAN, PR, 00918, with a listed phone of (787) 274-0277. NPI 1083774228 was issued on 12/11/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what MARRERO 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 717 prescription claims written by this provider, covering 92 Medicare beneficiaries and totaling roughly $20K in drug spend, split 5% brand-name and 95% 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.

Geriatric Medicine (Family Medicine) Physician is a narrow specialty nationwide, with 1,779 enrolled providers across 52 states and an average of 4,854 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

CESAR GONZALEZ #463 URB ROOSEVELT
SAN JUAN, PR 00918

Provider Details

NPI 1083774228
Specialty Geriatric Medicine (Family Medicine) Physician
Credentials MD
Gender Male
NPI Issued 12/11/2006

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 CARLOS MARRERO, MD. Source: openpaymentsdata.cms.gov.

Total received

$136

Largest payer

Medtronic, 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 · Generic-heavy

CARLOS MARRERO, MD — brand share 5.0%
Specialty average (est.)

5% brand-name claims vs 95% generic, on 717 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.

717
Total Claims
$20K
Total Drug Cost
92
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,245
Total Day Supply
33,693
Brand vs Generic
5% brand / 95% generic
Brand Drug Cost
$9K
Generic Drug Cost
$12K
Antibiotic Claims
58

Patient Demographics

Average Patient Age
74.6 years
Avg HCC Risk Score
1.07
Gender Split
61% female / 39% male

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Gabapentin
38
Atorvastatin Calcium
35
Fluticasone Propionate
31
Methylprednisolone
28
Montelukast Sodium
28
Alprazolam
26
Azithromycin
21
Irbesartan
21
Desloratadine
20
Celecoxib
19

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

Geriatric Medicine (Family Medicine) Physician Overview

How CARLOS MARRERO, MD fits within the Geriatric Medicine (Family Medicine) Physician landscape nationally.

1,779
Geriatric Medicine (Family Medicine) Physician Providers in US
52
States with Geriatric Medicine (Family Medicine) Physician
4,854
Avg Claims per Provider

CARLOS MARRERO, MD's 717 claims are below the specialty average of 4,854.

Nearby Geriatric Medicine (Family Medicine) Physician Providers in Puerto Rico

Other clinicians with the same primary specialty enrolled in Puerto Rico, drawn from the same CMS NPPES roster as MARRERO.

Compare Geriatric Medicine (Family Medicine) Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is CARLOS MARRERO, MD's specialty?
CARLOS MARRERO, MD specializes in Geriatric Medicine (Family Medicine) Physician and practices in SAN JUAN, Puerto Rico. Credentials: MD.
How much does CARLOS MARRERO, MD prescribe under Medicare Part D?
In 2023, CARLOS MARRERO, MD wrote 717 Medicare Part D claims totaling $20K in drug costs for 92 beneficiaries.
Where is CARLOS MARRERO, MD located?
CARLOS MARRERO, MD is located at CESAR GONZALEZ #463 URB ROOSEVELT, SAN JUAN, PR, 00918. Phone: (787) 274-0277.
What is CARLOS MARRERO, MD's NPI number?
CARLOS MARRERO, MD's National Provider Identifier (NPI) is 1083774228, issued on 12/11/2006.
Does CARLOS MARRERO, MD prescribe more brand-name or generic drugs?
CARLOS MARRERO, MD's prescribing is 5% brand-name and 95% generic drugs by claim count, with $9K in brand drug costs.
How many Geriatric Medicine (Family Medicine) Physician providers are there in the US?
There are 1,779 Geriatric Medicine (Family Medicine) Physician providers across 52 states in the US. The average Geriatric Medicine (Family Medicine) Physician provider writes 4,854 Medicare Part D claims per year.
What drugs does CARLOS MARRERO, MD prescribe most often?
Based on 2023 Medicare Part D data, CARLOS MARRERO, MD's most frequently prescribed drugs include Gabapentin, Atorvastatin Calcium, Fluticasone Propionate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does CARLOS MARRERO, MD accept Medicare?
CARLOS MARRERO, MD appears in CMS Medicare data with 717 Part D claims and 92 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify CARLOS MARRERO, MD's credentials?
CARLOS MARRERO, MD's NPI is 1083774228 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