This bill creates an official definition of what counts as an 'essential health system' in the Medicaid program. Essentially, it identifies hospitals that serve a lot of low-income and uninsured patients and gives them special recognition. To qualify, a hospital must be a regular Medicare hospital (not a specialty facility) that is either government-run or nonprofit, and it must show that it serves a high volume of Medicaid and low-income patients. The bill measures this by looking at whether the hospital has at least 35% of patients on Medicare's disproportionate share program, or meets certain other thresholds that show it's in the top tier of hospitals serving poor patients in its state. Once a hospital gets this 'essential health system' designation, it keeps it for 5 years and can be redesignated after that. The bill also requires MACPAC (a government advisory body) to publish a list of these hospitals every year and create a ranking system showing how each hospital compares to others in its area, state, and nationwide. The goal is to help policymakers identify which hospitals are critical for serving low-income communities and to support policies that help these hospitals stay financially stable while providing important services.