Quick answers
- Does Marielly Sierra Mercado accept Medicare assignment?
- Medicare's clinician data says Marielly Sierra Mercado may accept Medicare assignment (as of October 2, 2026). Ask the office whether they accept it for your visit.
- How many Medicare patients does Marielly Sierra Mercado see?
- In 2024, CMS data shows 44 Original Medicare patients and 154 services for Marielly Sierra Mercado. This counts Original Medicare only and measures volume, not quality.
- What is Marielly Sierra Mercado's NPI number?
- 1013258482. 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 Marielly Sierra Mercado, 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 | 44 |
|---|---|
| Services billed to Medicare | 154 |
| Different services or procedures | 8 |
| Participating Medicare provider | Yes |
| Average age of these patients | 75 |
Most frequent services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)68 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)60 services
- Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes (99222)13 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%
- Arthritis45%
- Chronic kidney disease34%
Hospitals where Marielly Sierra Mercado works
Medicare's Facility Affiliation Data lists Marielly Sierra Mercado 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.
- Bayamon Medical CenterBayamon, PR · Acute Care Hospital · Emergency services: listed by Medicare · CCN 400032
Practice locations
Addresses where Marielly Sierra Mercado is enrolled with Medicare (CMS data updated October 2, 2026).
- 382 Calle Manuel DomenechSan Juan, PR 00918 (787) 945‑7797
Specialties
- Endocrinologyprimary
Other endocrinologists in San Juan
Clinicians with the same Medicare primary specialty in San Juan, PR — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2011 (15 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1013258482 |
| 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