Medicare for All aims to provide universal healthcare coverage, reducing the number of uninsured individuals who might otherwise forgo necessary treatments due to cost. This can lead to earlier diagnosis and treatment, potentially saving lives that might be lost under a system where access is dependent on insurance coverage.

A 2009 study estimated that lack of health insurance was associated with 45,000 deaths annually in the U.S. A newer study published in the medical journal The Lancet in 2020 found that Medicare for all would prevent about 68,000 unnecessary deaths per year.

Opponents of M4A argue that a government-run healthcare system could lead to inefficiencies, mismanagement, and lower quality of care, ultimately resulting in higher mortality rates. However, evidence from other countries with universal healthcare systems doesn't support this claim. Notably, these countries spend about half as much per capita on healthcare as the U.S. and get better health outcomes.