Medical emergency?Emergency? Call 911. Nearest emergency roomsNearest ERs

Internal Medicine

Mariano R. Librojo, MD

Works at hospitals in Putnam, CT · New London, CT · Norwich, CT … · Connecticut

Summary

Mariano R. Librojo, MD (Internal Medicine) is listed by Medicare at 4 hospitals in Putnam, CT, New London, CT and Norwich, CT and other places. NPI 1689867533. Medicare data says the clinician accepts Medicare assignment. Source: CMS Facility Affiliation Data, updated 2026-10-02.

From official Medicare data

This page shows what Medicare's official clinician data says about Mariano R. Librojo, joined by NPI number (data updated 2026-10-02). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

At a glance

Internal MedicinePrimary specialty
YesAccepts Medicare assignment
23Years since medical school (graduated 2003)
MaleGender (as listed)
The William W Backus HospitalGroup practice (+1 more)

Quick answers

Which hospitals does Mariano R. Librojo work at?
Medicare's official clinician data lists Mariano R. Librojo at 4 hospitals: Day Kimball Hospital, Lawrence & Memorial Hospital, William W Backus Hospital and Windham Community Memorial Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
Where does Mariano R. Librojo see patients?
Medicare's clinician data lists 2 practice locations, including Willimantic, CT and Norwich, CT. Call before your visit to confirm the address.
What is Mariano R. Librojo's specialty?
Medicare lists Internal Medicine as the primary specialty.
Does Mariano R. Librojo accept Medicare assignment?
Yes. Medicare's clinician data says Mariano R. Librojo accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
What is the phone number for Mariano R. Librojo?
(860) 456-9116, as listed in official Medicare / NPI Registry data.
What is Mariano R. Librojo's NPI number?
1689867533. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Hospitals where Mariano R. Librojo works

Medicare's Facility Affiliation Data lists Mariano R. Librojo at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.

Practice locations

Addresses where Mariano R. Librojo is enrolled with Medicare (CMS data updated 2026-10-02).

Group practices

Medicare enrollment lists Mariano R. Librojo as a member of these groups (CMS data updated 2026-10-02).

  • The William W Backus Hospital249 clinicians in the group
  • Windham Community Memorial Hospital Inc64 clinicians in the group

Specialties

Find other Internal Medicine doctors in Connecticut →

Other internal medicine doctors in Willimantic

Clinicians with the same Medicare primary specialty in Willimantic, CT — not a recommendation.

All internal medicine doctors in Willimantic →

Clinician information

CredentialMD
Graduation year2003
Gender (as listed)Male
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1689867533
CorrectionsReport 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

  1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
  2. National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
  3. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  4. Medicare Care Compare — official Medicare tool to look up clinicians