Under M4A, the influx of new patients into the healthcare system could overwhelm providers, resulting in longer wait times for appointments, surgeries, and procedures. Countries with universal healthcare, like Canada, have experienced issues with wait times for certain procedures. A 2022 poll also shows that Canadians are less satisfied with their access to healthcare than Americans.

When healthcare is guaranteed, people may become less responsible for their own health, adopting unhealthy lifestyles or neglecting preventive measures, knowing that treatment will always be available.