| Mayo Clinic Health System-Franciscan Medical Center Inc | La Crosse, WI | Acute Care Hospitals | 5 stars |
| Mayo Clinic Health System-Northland | Barron, WI | Critical Access Hospitals | 4 stars |
| Mayo Clinic Health System-Red Cedar Inc | Menomonie, WI | Critical Access Hospitals | 3 stars |
| Mayo Clinic Hospital | Phoenix, AZ | Acute Care Hospitals | 5 stars |
| McCullough-Hyde Memorial Hospital | Oxford, OH | Acute Care Hospitals | 3 stars |
| McCurtain Memorial Hospital | Idabel, OK | Critical Access Hospitals | 4 stars |
| McDowell ARH Hospital | Mc Dowell, KY | Critical Access Hospitals | Not rated |
| McGehee Hospital | McGehee, AR | Critical Access Hospitals | Not rated |
| McKenzie County Healthcare Systems Inc | Watford City, ND | Critical Access Hospitals | Not rated |
| McKenzie Health System | Sandusky, MI | Critical Access Hospitals | Not rated |
| McKenzie-Willamette Medical Center | Springfield, OR | Acute Care Hospitals | 4 stars |
| McLaren Bay Region | Bay City, MI | Acute Care Hospitals | 1 star |
| McLaren Caro Region | Caro, MI | Critical Access Hospitals | Not rated |
| McLaren Central Michigan | Mount Pleasant, MI | Acute Care Hospitals | 3 stars |
| McLaren Flint | Flint, MI | Acute Care Hospitals | 2 stars |
| McLaren Greater Lansing | Lansing, MI | Acute Care Hospitals | 3 stars |
| McLaren Lapeer Region | Lapeer, MI | Acute Care Hospitals | 2 stars |
| McLaren Macomb | Mount Clemens, MI | Acute Care Hospitals | 1 star |
| McLaren Oakland | Pontiac, MI | Acute Care Hospitals | 2 stars |
| McLaren Port Huron | Port Huron, MI | Acute Care Hospitals | 2 stars |
| McLaren Thumb Region | Bad Axe, MI | Critical Access Hospitals | 5 stars |
| McLean Hospital Corporation | Belmont, MA | Psychiatric | Not rated |
| McLeod Health Cheraw | Cheraw, SC | Acute Care Hospitals | 3 stars |
| McLeod Health Clarendon | Manning, SC | Acute Care Hospitals | 3 stars |
| McLeod Loris Hospital | Loris, SC | Acute Care Hospitals | 4 stars |
| McLeod Medical Center - Dillon | Dillon, SC | Acute Care Hospitals | 3 stars |
| McLeod Regional Medical Center-Pee Dee | Florence, SC | Acute Care Hospitals | 3 stars |
| McPherson Hospital | McPherson, KS | Acute Care Hospitals | 2 stars |
| Meadville Medical Center | Meadville, PA | Acute Care Hospitals | 4 stars |
| Mease Countryside Hospital | Safety Harbor, FL | Acute Care Hospitals | 4 stars |
| Mease Dunedin Hospital | Dunedin, FL | Acute Care Hospitals | 4 stars |
| Medical Center of the Rockies | Loveland, CO | Acute Care Hospitals | 5 stars |
| Medical City Alliance | Fort Worth, TX | Acute Care Hospitals | 3 stars |
| Medical City Lewisville | Lewisville, TX | Acute Care Hospitals | 3 stars |
| Medina Hospital | Medina, OH | Acute Care Hospitals | 5 stars |
| Medina Memorial Hospital | Medina, NY | Critical Access Hospitals | Not rated |
| Medstar Franklin Square Medical Center | Rosedale, MD | Acute Care Hospitals | 3 stars |
| Medstar Harbor Hospital | Baltimore, MD | Acute Care Hospitals | 4 stars |
| Medstar Montgomery Medical Center | Olney, MD | Acute Care Hospitals | 3 stars |
| Medstar Saint Mary's Hospital | Leonardtown, MD | Acute Care Hospitals | 4 stars |
| Medstar Southern Maryland Hospital Center | Clinton, MD | Acute Care Hospitals | 2 stars |
| Melrosewakefield Healthcare | Melrose, MA | Acute Care Hospitals | 3 stars |
| Memorial Community Hospital & Health System | Blair, NE | Critical Access Hospitals | Not rated |
| Memorial Health Care Systems | Seward, NE | Critical Access Hospitals | 3 stars |
| Memorial Hermann - Texas Medical Center | Houston, TX | Acute Care Hospitals | 4 stars |
| Memorial Hermann Hospital System | Houston, TX | Acute Care Hospitals | 3 stars |
| Memorial Hermann Katy Hospital | Katy, TX | Acute Care Hospitals | 3 stars |
| Memorial Hermann Memorial City Hospital | Houston, TX | Acute Care Hospitals | 4 stars |
| Memorial Hermann Northeast Hospital | Humble, TX | Acute Care Hospitals | 3 stars |
| Memorial Hermann Sugar Land Hospital | Sugar Land, TX | Acute Care Hospitals | 4 stars |