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Psychiatry

Marissa J. Martz, MD

Sees patients in Grand Rapids, MI · Michigan

Summary

Dr. Marissa J. Martz, MD is a psychiatrist at 300 68th St SE, Grand Rapids, MI 49548. Phone: (616) 455-5000. Accepts Medicare assignment. In 2024, Marissa J. Martz had 40 Original Medicare patients and 263 services. NPI 1275063919. Source: CMS National Downloadable File, updated October 2, 2026; CMS Medicare Physician & Other Practitioners, data year 2024.

  • Specialty: Psychiatrist (Medicare lists Psychiatry)
  • Address: 300 68th St SE, Grand Rapids, MI 49548 · Directions
  • Phone: (616) 455‑5000
  • Medicare: Accepts Medicare assignment
  • Group practice: Pine Rest Christian Mental Health Services
  • Medical school: Michigan State University College Of Human Medicine · graduated 2017 (9 years since medical school)
  • Gender (as listed): Female

From official Medicare data

This page shows what Medicare's official clinician data says about Marissa J. Martz, joined by NPI number (data updated October 2, 2026). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

Quick answers

Does Marissa J. Martz accept Medicare assignment?
Yes. Medicare's clinician data says Marissa J. Martz 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 Marissa J. Martz see?
In 2024, CMS data shows 40 Original Medicare patients and 263 services for Marissa J. Martz. This counts Original Medicare only and measures volume, not quality.
What is Marissa J. Martz's NPI number?
1275063919. 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 Marissa J. Martz, 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 patients40
Services billed to Medicare263
Different services or procedures6
Participating Medicare providerYes
Average age of these patients47

Most frequent services

  1. Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)191 services
  2. Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes (99223)23 services
  3. Hospital discharge day management, more than 30 minutes (99239)23 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).

  • Anxiety75%
  • Depression53%
  • High blood pressure45%
  • High cholesterol43%

Practice locations

Addresses where Marissa J. Martz is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists Marissa J. Martz as a member of this group (CMS data updated October 2, 2026).

  • Pine Rest Christian Mental Health Services353 clinicians in the group

Specialties

Find other Psychiatry doctors in Michigan →

Other psychiatrists in Grand Rapids

Clinicians with the same Medicare primary specialty in Grand Rapids, MI — not a recommendation.

All psychiatrists in Grand Rapids →

Other clinicians in Pine Rest Christian Mental Health Services

Medicare enrollment lists these clinicians in the same group practice — not a recommendation.

Clinician information

CredentialMD
Medical schoolMichigan State University College Of Human Medicine
Graduation year2017 (9 years since medical school)
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1275063919
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. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
  2. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
  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