Quick answers
- Does Marcus Santiago Hernandez accept Medicare assignment?
- Yes. Medicare's clinician data says Marcus Santiago Hernandez accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does Marcus Santiago Hernandez see?
- In 2024, CMS data shows 77 Original Medicare patients and 255 services for Marcus Santiago Hernandez. This counts Original Medicare only and measures volume, not quality.
- What is Marcus Santiago Hernandez's NPI number?
- 1619080389. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for Marcus Santiago Hernandez, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 77 |
|---|---|
| Services billed to Medicare | 255 |
| Different services or procedures | 9 |
| Participating Medicare provider | Yes |
| Average age of these patients | 78 |
Most frequent services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)196 services
- Telephone medical discussion with physician, 11-20 minutes (99442)13 services
- New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more (99203)12 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High blood pressure75%
- High cholesterol75%
- Diabetes75%
- Chronic kidney disease69%
- Arthritis52%
- Osteoporosis30%
Hospitals where Marcus Santiago Hernandez works
Medicare's Facility Affiliation Data lists Marcus Santiago Hernandez at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- Presbyterian Community HospitalSan Juan, PR · Acute Care Hospital · Emergency services: listed by Medicare · CCN 400001
Practice locations
Addresses where Marcus Santiago Hernandez is enrolled with Medicare (CMS data updated October 2, 2026).
- Ashford Medical Ctr Ofic, 805 Calle WashingtonSan Juan, PR 00907 (787) 600‑6411
Specialties
- Internal Medicineprimary
Other internal medicine doctors in San Juan
Clinicians with the same Medicare primary specialty in San Juan, PR — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1982 (44 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1619080389 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians