Quick answers
- Does Shawn Marein accept Medicare assignment?
- Yes. Medicare's clinician data says Shawn Marein 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 Shawn Marein see?
- In 2024, CMS data shows 179 Original Medicare patients and 494 services for Shawn Marein. This counts Original Medicare only and measures volume, not quality.
- What is Shawn Marein's NPI number?
- 1265964878. 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 Shawn Marein, 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 | 179 |
|---|---|
| Services billed to Medicare | 494 |
| Different services or procedures | 43 |
| Participating Medicare provider | Yes |
| Average age of these patients | 74 |
Most frequent services
- Critical care, first 30-74 minutes (99291)109 services
- Test to measure expiratory airflow and volume changes before and after medication administration (94060)51 services
- Test to examine how well the lungs exchange gases (94729)47 services
- Test to determine lung volumes using sensors (94726)44 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)39 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 blood pressure75%
- High cholesterol75%
- COPD55%
- Arthritis48%
- Ischemic heart disease42%
- Chronic kidney disease42%
Hospitals where Shawn Marein works
Medicare's Facility Affiliation Data lists Shawn Marein 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.
- Corewell Health Watervliet HospitalWatervliet, MI · Acute Care Hospital · Emergency services: listed by Medicare · CCN 230078
- Lakeland Hospital, St JosephSt Joseph, MI · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 230021
Practice locations
Addresses where Shawn Marein is enrolled with Medicare (CMS data updated October 2, 2026).
- 1234 Napier AveSaint Joseph, MI 49085 (269) 983‑8300
- 1234 Napier Ave, Corewell Health Lakeland HospitalsSaint Joseph, MI 49085 (269) 983‑8300
Group practices
Medicare enrollment lists Shawn Marein as a member of these groups (CMS data updated October 2, 2026).
- Lakeland Medical Practices281 clinicians in the group
- Lakeland Hospitals at Niles and St Joseph Inc131 clinicians in the group
Specialties
- Pulmonary Diseaseprimary
Other pulmonologists in Saint Joseph
Clinicians with the same Medicare primary specialty in Saint Joseph, MI — not a recommendation.
Other clinicians in Lakeland Medical Practices
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Graduation year | 2017 (9 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1265964878 |
| 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