Quick answers
- Does Zachary S. Grunau accept Medicare assignment?
- Yes. Medicare's clinician data says Zachary S. Grunau 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 Zachary S. Grunau see?
- In 2024, CMS data shows 28 Original Medicare patients and 116 services for Zachary S. Grunau. This counts Original Medicare only and measures volume, not quality.
- What is Zachary S. Grunau's NPI number?
- 1568952349. 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 Zachary S. Grunau, 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 | 28 |
|---|---|
| Services billed to Medicare | 116 |
| Different services or procedures | 4 |
| Participating Medicare provider | Yes |
| Average age of these patients | 55 |
Most frequent services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)105 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).
- Depression75%
- Anxiety75%
- High blood pressure57%
- High cholesterol50%
- Arthritis43%
- Asthma39%
Hospitals where Zachary S. Grunau works
Medicare's Facility Affiliation Data lists Zachary S. Grunau 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.
- Newton-Wellesley HospitalNewton, MA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 220101
Practice locations
Addresses where Zachary S. Grunau is enrolled with Medicare (CMS data updated October 2, 2026).
- 2014 Washington StNewton, MA 02462 (617) 243‑6000
Group practices
Medicare enrollment lists Zachary S. Grunau as a member of this group (CMS data updated October 2, 2026).
- Mass General Brigham Medical Group Suburban Massachusetts Inc602 clinicians in the group
Specialties
- Psychiatryprimary
Other psychiatrists in Newton
Clinicians with the same Medicare primary specialty in Newton, MA — not a recommendation.
Other clinicians in Mass General Brigham Medical Group Suburban Massachusetts Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Tulane University School Of Medicine |
| Graduation year | 2018 (8 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1568952349 |
| 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