NPI registry status
Active
2026 NPPES data Endocrinology, Diabetes & Metabolism Physician NPI 1821306127 M.D.
Verify on CMS → Milliette Alvarado-Santiago, M.D.
Endocrinology, Diabetes & Metabolism Physician in Rio Piedras, 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 7,852 in Endocrinology, Diabetes & Metabolism 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 · 187 beneficiaries · Endocrinology, Diabetes & Metabolism Physician avg: 3K
Generic prescribing
34%
generic claims · 64% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$37.9K
102 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
Milliette Alvarado-Santiago, M.D. filed 2,194 Medicare Part D claims in 2023 as a Endocrinology, Diabetes & Metabolism Physician in Rio Piedras, Puerto Rico, prescribing 34% generic.
- 2K
- Part D claims, 2023
- 34%
- 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.
Milliette Alvarado-Santiago, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
2,194 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)
Milliette Alvarado-Santiago, M.D. 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 Milliette Alvarado-Santiago, M.D.?
Quality data not reportedPrimary specialty
Endocrinology, Diabetes & Metabolism Physician
Medicare Part D claims
2,194 17% vs specialty avg
Specialty distribution in Puerto Rico
How Endocrinology, Diabetes & Metabolism 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 Endocrinology, Diabetes & Metabolism 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).
Milliette Alvarado-Santiago, M.D. appears in the CMS NPPES registry as a Endocrinology, Diabetes & Metabolism Physician provider holding M.D. credentials at CLINICA DE LA ESCUELA DE MEDICINA, Rio Piedras, PR, 00921, with a listed phone of (787) 758-7908. NPI 1821306127 was issued on 09/21/2010.
Medicare Part D records for calendar year 2023 show 2,194 prescription claims written by this provider, covering 187 Medicare beneficiaries and totaling roughly $612K in drug spend, split 64% brand-name and 34% generic by claim count.
Endocrinology, Diabetes & Metabolism Physician is a mid-sized specialty nationwide, with 7,852 enrolled providers across 54 states and an average of 2,639 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 | 1821306127 |
|---|---|
| Specialty | Endocrinology, Diabetes & Metabolism Physician |
| Credentials | M.D. |
| Gender | Female |
| NPI Issued | 09/21/2010 |
Hospital and facility affiliations
Facilities where Milliette Alvarado-Santiago, M.D. 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.
Pro Health Clinical Services LLC
Bayamon, PR
Recinto DE Ciencias Medicas
Carolina, PR
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 Milliette Alvarado-Santiago, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$37.9K
Largest payer
Lilly USA, LLC
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 · Brand-heavy
Milliette Alvarado-Santiago, M.D. - brand share 64.0%
Endocrinology, Diabetes & Metabolism Physician average
64% brand-name claims vs 34% generic, on 2,194 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.
2,194
Total Claims
$612K
Total Drug Cost
187
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 2,845
- Total Day Supply
- 83,698
- Brand vs Generic
- 64% brand / 34% generic
- Brand Drug Cost
- $601K
- Generic Drug Cost
- $10K
Patient Demographics
- Average Patient Age
- 69.9 years
- Avg HCC Risk Score
- 1.91
- Gender Split
- 69% female / 31% male
- Age Distribution
- <65: 42, 65-74: 94, 75-84: 39, 85+: 12
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Milliette Alvarado-Santiago, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Synthroid
Synthroid
548 claims
- Ozempic 145
Ozempic
145 claims
- Trulicity 114
Trulicity
114 claims
- Metformin Hcl Er 113
Metformin Hcl Er
113 claims
- Janumet Xr 85
Janumet Xr
85 claims
- Humalog 82
Humalog
82 claims
- Atorvastatin Calcium 73
Atorvastatin Calcium
73 claims
- Rosuvastatin Calcium 66
Rosuvastatin Calcium
66 claims
| Drug | Claims |
|---|---|
| Synthroid Levothyroxine Sodium | 548 |
| Ozempic Semaglutide | 145 |
| Trulicity Dulaglutide | 114 |
| Metformin Hcl Er Metformin Hcl | 113 |
| Janumet Xr Sitagliptin Phos/Metformin Hcl | 85 |
| Humalog Insulin Lispro | 82 |
| Atorvastatin Calcium | 73 |
| Rosuvastatin Calcium | 66 |
| Metformin Hcl | 57 |
| Farxiga Dapagliflozin Propanediol | 48 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
More Endocrinology, Diabetes & Metabolism Physician in PR →
All providers in Puerto Rico →
Compare specialties →
Endocrinology, Diabetes & Metabolism Physician Overview
How Milliette Alvarado-Santiago, M.D. fits within the Endocrinology, Diabetes & Metabolism Physician landscape nationally.
7,852
Endocrinology, Diabetes & Metabolism Physician Providers in US
54
States with Endocrinology, Diabetes & Metabolism Physician
2,639
Avg Claims per Provider
Milliette Alvarado-Santiago, M.D.'s 2,194 claims are below the specialty average of 2,639.
Nearby Endocrinology, Diabetes & Metabolism Physician Providers in Puerto Rico
Other clinicians with the same primary specialty enrolled in Puerto Rico, drawn from the same CMS NPPES roster as Alvarado-Santiago.
Dr. Anardi Agosto Mujica
M.D.
Cayey, PR
Dr. Manuel Alegre-Hernandez
MD
San Juan, PR
Dr. Myriam Allende-Vigo
MD
Humacao, PR
Dr. Isabel Arroyo Gomez
MD
San Juan, PR
Natalia Burgos Polanco
San Juan, PR
Compare Endocrinology, Diabetes & Metabolism 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 Endocrinology, Diabetes & Metabolism 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 Puerto Rico
Frequently Asked Questions
What is Milliette Alvarado-Santiago, M.D.'s specialty? ▼
Milliette Alvarado-Santiago, M.D. specializes in Endocrinology, Diabetes & Metabolism Physician and practices in Rio Piedras, Puerto Rico. Credentials: M.D..
How much does Milliette Alvarado-Santiago, M.D. prescribe under Medicare Part D? ▼
In 2023, Milliette Alvarado-Santiago, M.D. wrote 2,194 Medicare Part D claims totaling $612K in drug costs for 187 beneficiaries.
Where is Milliette Alvarado-Santiago, M.D. located? ▼
Milliette Alvarado-Santiago, M.D. is located at CLINICA DE LA ESCUELA DE MEDICINA, Rio Piedras, PR, 00921. Phone: (787) 758-7908.
What is Milliette Alvarado-Santiago, M.D.'s NPI number? ▼
Milliette Alvarado-Santiago, M.D.'s National Provider Identifier (NPI) is 1821306127, issued on 09/21/2010.
Does Milliette Alvarado-Santiago, M.D. prescribe more brand-name or generic drugs? ▼
Milliette Alvarado-Santiago, M.D.'s prescribing is 64% brand-name and 34% generic drugs by claim count, with $601K in brand drug costs.
How many Endocrinology, Diabetes & Metabolism Physician providers are there in the US? ▼
There are 7,852 Endocrinology, Diabetes & Metabolism Physician providers across 54 states in the US. The average Endocrinology, Diabetes & Metabolism Physician provider writes 2,639 Medicare Part D claims per year.
What drugs does Milliette Alvarado-Santiago, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Milliette Alvarado-Santiago, M.D.'s most frequently prescribed drugs include Synthroid, Ozempic, Trulicity. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Milliette Alvarado-Santiago, M.D. accept Medicare? ▼
Milliette Alvarado-Santiago, M.D. appears in CMS Medicare data with 2,194 Part D claims and 187 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Milliette Alvarado-Santiago, M.D.'s credentials? ▼
Milliette Alvarado-Santiago, M.D.'s NPI is 1821306127 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.