Quick answers
- Does Nestor A. Sainz Rueda accept Medicare assignment?
- Yes. Medicare's clinician data says Nestor A. Sainz Rueda 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 Nestor A. Sainz Rueda see?
- In 2024, CMS data shows 110 Original Medicare patients and 193 services for Nestor A. Sainz Rueda. This counts Original Medicare only and measures volume, not quality.
- What is Nestor A. Sainz Rueda's NPI number?
- 1003444563. 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 Nestor A. Sainz Rueda, 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 | 110 |
|---|---|
| Services billed to Medicare | 193 |
| Different services or procedures | 19 |
| Participating Medicare provider | Yes |
| Average age of these patients | 76 |
Most frequent services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)65 services
- Insertion of needle into vein for collection of blood sample (36415)31 services
- Annual depression screening, 5 to 15 minutes (G0444)19 services
- Annual alcohol misuse screening, 5 to 15 minutes (G0442)18 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)16 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 cholesterol75%
- High blood pressure74%
- Arthritis36%
- Ischemic heart disease29%
- Depression26%
- Anxiety25%
Hospitals where Nestor A. Sainz Rueda works
Medicare's Facility Affiliation Data lists Nestor A. Sainz Rueda 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.
- Brigham and Women Faulkner HospitalJamaica Plain, MA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 220119
- Brigham and Women's HospitalBoston, MA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 220110
- Massachusetts Eye and Ear Infirmary -Boston, MA · Acute Care Hospital · Emergency services: listed by Medicare · CCN 220075
- Massachusetts General HospitalBoston, MA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 220071
- North Shore Medical Center -Salem, MA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 220035
Practice locations
Addresses where Nestor A. Sainz Rueda is enrolled with Medicare (CMS data updated October 2, 2026).
- 55 Fruit StBoston, MA 02114 (617) 726‑2000
Group practices
Medicare enrollment lists Nestor A. Sainz Rueda as a member of these groups (CMS data updated October 2, 2026).
- Massachusetts General Physicians Organization Inc3,558 clinicians in the group
- The General Hospital Corporation1,267 clinicians in the group
Specialties
- Family Practiceprimary
Other family doctors in Boston
Clinicians with the same Medicare primary specialty in Boston, MA — not a recommendation.
Other clinicians in Massachusetts General Physicians Organization Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1999 (27 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) | 1003444563 |
| 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