NPI registry status
Active
2026 NPPES data General Practice Physician NPI 1861432486 M.D.
Verify on CMS → Mayra Fernandez Amarat, M.D.
General Practice Physician in Loiza, Puerto Rico.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 16,725 in General Practice 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
412
Medicare Part D claims · 59 beneficiaries · General Practice Physician avg: 3K
Generic prescribing
85%
generic claims · 12% brand-name · higher generic rates reduce patient out-of-pocket costs
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
Mayra Fernandez Amarat, M.D. filed 412 Medicare Part D claims in 2023 as a General Practice Physician in Loiza, Puerto Rico, prescribing 85% generic.
- 412
- Part D claims, 2023
- 85%
- generic prescribing
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.
Mayra Fernandez Amarat, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
412 Top 38% higher than 62% 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
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Board-eligible specialty (heuristic, not verified)
Mayra Fernandez Amarat, M.D. 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 Mayra Fernandez Amarat, M.D.?
Quality data not reportedPrimary specialty
General Practice Physician
Medicare Part D claims
412 86% vs specialty avg
Specialty distribution in Puerto Rico
How General Practice Physician compares to other specialties among Puerto Rico 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 General Practice 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).
Mayra Fernandez Amarat, M.D. appears in the CMS NPPES registry as a General Practice Physician provider holding M.D. credentials at CARR 188 # INT187, Loiza, PR, 00772, with a listed phone of (939) 640-7983. NPI 1861432486 was issued on 06/08/2006.
Medicare Part D records for calendar year 2023 show 412 prescription claims written by this provider, covering 59 Medicare beneficiaries and totaling roughly $20K in drug spend, split 12% brand-name and 85% generic by claim count.
General Practice Physician is a mid-sized specialty nationwide, with 16,725 enrolled providers across 56 states and an average of 2,872 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 | 1861432486 |
|---|---|
| Specialty | General Practice Physician |
| Credentials | M.D. |
| Gender | Female |
| NPI Issued | 06/08/2006 |
Brand vs generic prescribing mix · Typical
Mayra Fernandez Amarat, M.D. - brand share 12.0%
General Practice Physician average
12% brand-name claims vs 85% generic, on 412 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.
412
Total Claims
$20K
Total Drug Cost
59
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 572
- Total Day Supply
- 16,478
- Brand vs Generic
- 12% brand / 85% generic
- Brand Drug Cost
- $14K
- Generic Drug Cost
- $6K
Patient Demographics
- Average Patient Age
- 72.3 years
- Avg HCC Risk Score
- 1.32
- Gender Split
- 64% female / 36% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Mayra Fernandez Amarat, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Famotidine
Famotidine
22 claims
- Atorvastatin Calcium
Atorvastatin Calcium
21 claims
- Losartan Potassium
Losartan Potassium
20 claims
- Lisinopril
Lisinopril
19 claims
- Synthroid
Synthroid
16 claims
- Montelukast Sodium
Montelukast Sodium
15 claims
- Pantoprazole Sodium
Pantoprazole Sodium
14 claims
- Metformin Hcl
Metformin Hcl
13 claims
| Drug | Claims |
|---|---|
| Famotidine | 22 |
| Atorvastatin Calcium | 21 |
| Losartan Potassium | 20 |
| Lisinopril | 19 |
| Synthroid Levothyroxine Sodium | 16 |
| Montelukast Sodium | 15 |
| Pantoprazole Sodium | 14 |
| Metformin Hcl | 13 |
| Metoprolol Succinate | 13 |
| Furosemide | 12 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
General Practice Physician Overview
How Mayra Fernandez Amarat, M.D. fits within the General Practice Physician landscape nationally.
16,725
General Practice Physician Providers in US
56
States with General Practice Physician
2,872
Avg Claims per Provider
Mayra Fernandez Amarat, M.D.'s 412 claims are below the specialty average of 2,872.
Nearby General Practice Physician Providers in Puerto Rico
Other clinicians with the same primary specialty enrolled in Puerto Rico, drawn from the same CMS NPPES roster as Fernandez Amarat.
Dr. Veronica Abraham
MD
San Juan, PR
Dr. Manuel Abraham Gonzalez
M.D.
San Juan, PR
Dr. Jennifer Abraham Vega
MD
San Juan, PR
Dr. Jose M. Abreu Guzman
M.D.
Manati, PR
Dr. Steven Abreu Reyes
M.D.
Las Piedras, PR
Compare General Practice 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 Puerto Rico medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby General Practice 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.
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Frequently Asked Questions
What is Mayra Fernandez Amarat, M.D.'s specialty? ▼
Mayra Fernandez Amarat, M.D. specializes in General Practice Physician and practices in Loiza, Puerto Rico. Credentials: M.D..
How much does Mayra Fernandez Amarat, M.D. prescribe under Medicare Part D? ▼
In 2023, Mayra Fernandez Amarat, M.D. wrote 412 Medicare Part D claims totaling $20K in drug costs for 59 beneficiaries.
Where is Mayra Fernandez Amarat, M.D. located? ▼
Mayra Fernandez Amarat, M.D. is located at CARR 188 # INT187, Loiza, PR, 00772. Phone: (939) 640-7983.
What is Mayra Fernandez Amarat, M.D.'s NPI number? ▼
Mayra Fernandez Amarat, M.D.'s National Provider Identifier (NPI) is 1861432486, issued on 06/08/2006.
Does Mayra Fernandez Amarat, M.D. prescribe more brand-name or generic drugs? ▼
Mayra Fernandez Amarat, M.D.'s prescribing is 12% brand-name and 85% generic drugs by claim count, with $14K in brand drug costs.
How many General Practice Physician providers are there in the US? ▼
There are 16,725 General Practice Physician providers across 56 states in the US. The average General Practice Physician provider writes 2,872 Medicare Part D claims per year.
What drugs does Mayra Fernandez Amarat, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Mayra Fernandez Amarat, M.D.'s most frequently prescribed drugs include Famotidine, Atorvastatin Calcium, Losartan Potassium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Mayra Fernandez Amarat, M.D. accept Medicare? ▼
Mayra Fernandez Amarat, M.D. appears in CMS Medicare data with 412 Part D claims and 59 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Mayra Fernandez Amarat, M.D.'s credentials? ▼
Mayra Fernandez Amarat, M.D.'s NPI is 1861432486 with credentials M.D.. 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.
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.