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MARIELLY SIERRA MERCADO M.D.
NPI 1013258482
Internal Medicine - Endocrinology, Diabetes & Metabolism in San Juan, PR

Active since March 11, 2013PECOS Enrolled
UNIVERSITY DISTRICT HOSPITAL, MEDICAL CENTER BO MONACILLOS, SAN JUAN, PR 00935(787) 754-0101 Get Directions Write a Review

NPPES record last updated: July 26, 2018. Verified against the NPPES registry weekly; last sync: November 01, 2026.

Record update history: Jul 26, 2018, Mar 19, 2017 (2 updates tracked since 2017).

About Marielly Sierra Mercado M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

MARIELLY SIERRA MERCADO M.D. (NPI 1013258482) is an individual endocrinology, diabetes & metabolism provider in San Juan, Puerto Rico, licensed in Puerto Rico (19192) and active in the NPI registry since March 2013. She is enrolled in Medicare PECOS, is affiliated with Bayamon Medical Center, and is a graduate of Other (2011).

NPPES Registry Identity

NPI1013258482
Entity TypeIndividualFemale
Primary Taxonomy207RE0101X
Provider Legal NameMARIELLY SIERRA MERCADOCredential: M.D.
Location AddressUNIVERSITY DISTRICT HOSPITAL, MEDICAL CENTER BO MONACILLOSSan Juan, PR 00935
Mailing AddressPo Box 366791San Juan, PR 00936-6791 · (787) 754-0101
Phone(787) 754-0101
Sole ProprietorYes
Medical School CMSOtherGraduated 2011
Enumeration DateMarch 11, 2013
Last NPPES UpdateJuly 26, 20182 updates tracked since enumeration
✔ NPI 1013258482 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal Medicine · Endocrinology, Diabetes & MetabolismAllopathic & Osteopathic Physicians
Taxonomy Code207RE0101X
License✔ Licensed in PR · 19192
Definition
An internist who concentrates on disorders of the internal (endocrine) glands such as the thyroid and adrenal glands. This specialist also deals with disorders such as diabetes, metabolic and nutritional disorders, obesity, pituitary diseases and menstrual and sexual problems.
Also ListedInternal MedicineTaxonomy 207R00000X · License 19192 (PR)

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Marielly Sierra Mercado M.d. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

PECOS PAC ID1153669213
PECOS Enrollment IDI20190214002620
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

2

Medicare enrollment records show Marielly Sierra Mercado reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Pro-Health Clinical Services LLC
Endocrinology, Diabetes & Metabolism
CALLE MANUEL ROSSY ESQUINA ISABEL SEGUNDA, BAYAMON HEALTH CENTER
Bayamon, PR 00961
  • Reassigned Medicare billing, Puerto Rico enrollment
  • 37 clinicians in this Medicare group
NPI 1881003382 (787) 451-1363
United Endocrinology Services
Endocrinology, Diabetes & Metabolism
U3 CARRETERA 21, URBANIZACION LAS LOMAS
San Juan, PR 00921
  • Reassigned Medicare billing, Puerto Rico enrollment
NPI 1760969109 (787) 518-0478

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 3

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232
Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.
68 services12 patients
Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213
This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.
60 services32 patients
Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 99222
Initial hospital inpatient care is a service where a healthcare provider spends about 50 minutes per day overseeing your care while you're admitted in the hospital. This includes reviewing your health status, planning your treatment, and ensuring your safety and comfort.
13 services11 patients

Hospital Affiliations CMS Care Compare

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Bayamon Medical Center

Acute Care Hospitals · Bayamon, PR
OwnershipProprietary
CMS Certification Number400032
LocationCarretera #2 Km 11 7Bayamon, PR 00960 · Bayamon County
Emergency services

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 00935 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$130.65 typical visit price
range $56.86 – $172.44
Typical copayment $32.66 (range $14.21 – $43.11)
Most-billed visit code 99204
Established Patient
$100.24 typical visit price
range $18.24 – $140.44
Typical copayment $25.06 (range $4.56 – $35.11)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES 20

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

DR. CESAR GABRIEL GOMEZ M.D.
Student in an Organized Health Care Education/Training Program
UNIVERSITY DISTRICT HOSPITAL, PUERTO RICO MEDICAL CENTER BO. MONACILLOS
SAN JUAN, PR 00935
San Juan Municipio (787) 754-0101
ALISHA MARIE SUBERVI-VAZQUEZ MD, MPH, MSC
Psychiatry & Neurology (Psychiatry)
UNIVERSITY DISTRICT HOSPITAL, PUERTO RICO MEDICAL CENTER
SAN JUAN, PR 00935
San Juan Municipio (787) 754-0101
STELLA MARIS BAEZ CORUJO M.D
Internal Medicine (Pulmonary Disease)
UNIVERSITY DISTRICT HOSPITAL, PUERTO RICO MEDICAL CAMPUS BO. MONACILLOS
SAN JUAN, PR 00935
San Juan Municipio (787) 754-0101
JOSUE DANIEL ANDINO VEGA
Internal Medicine
UNIVERSITY DISTRICT HOSPITAL
SAN JUAN, PR 00935
San Juan Municipio (787) 754-0101
DAVID BEATON COMULADA M.D
Orthopaedic Surgery
UNIVERSITY DISTRICT HOSPITAL, BO , MONACILLOS
SAN JUAN, PR 00935
San Juan Municipio (787) 754-0101
YADIRIS VAZQUEZ DIAZ
Internal Medicine
UNIVERSITY DISTRICT HOSPITAL
SAN JUAN, PR 00935
San Juan Municipio (787) 754-0101
JOSE ROQUE TORRES MD
Internal Medicine
UNIVERSITY DISTRICT HOSPITAL
SAN JUAN, PR 00935
San Juan Municipio (787) 754-0101
DR. PEDRO ACEVEDO MD
Anesthesiology
UNIVERSITY DISTRICT HOSPITAL, PUERTO RICO MEDICAL CENTER
SAN JUAN, PR 00935
San Juan Municipio (787) 754-0101

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Marielly Sierra Mercado's NPI number?

The NPI number for Marielly Sierra Mercado is 1013258482. It was assigned to this individual provider in the NPPES registry on March 11, 2013.

Where is Marielly Sierra Mercado located?

Marielly Sierra Mercado practices at University District Hospital Medical Center Bo Monacillos, San Juan, PR 00935. The listed phone number is (787) 754-0101.

What is Marielly Sierra Mercado's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Endocrinology, Diabetes & Metabolism, with taxonomy code 207RE0101X.

Is Marielly Sierra Mercado enrolled in Medicare?

Yes. Marielly Sierra Mercado is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Marielly Sierra Mercado's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Marielly Sierra Mercado reassigns Medicare benefits to 2 organizations: Pro-Health Clinical Services LLC (Bayamon, PR) and United Endocrinology Services (San Juan, PR). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Marielly Sierra Mercado's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

Is Marielly Sierra Mercado affiliated with any hospitals?

According to CMS data, Marielly Sierra Mercado is affiliated with Bayamon Medical Center.

When was this NPI record last updated?

The NPPES record for Marielly Sierra Mercado was last updated on July 26, 2018. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 8 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.