What significant change regarding coverage did the ACA implement in 2010?

The significant change regarding coverage implemented by the Affordable Care Act (ACA) in 2010 is the assurance of continuous coverage for individuals with pre-existing conditions. Before the ACA, insurance companies could deny coverage or charge higher premiums to individuals based on their health history. This meant that someone with a chronic illness or prior health issues could struggle to access the healthcare they needed.

With the ACA's provision, insurers are prohibited from discriminating against individuals with pre-existing conditions, ensuring that they cannot be denied coverage or charged exorbitantly higher rates solely based on their health history. This major reform aimed to enhance accessibility to healthcare and protect millions of Americans from being uninsured due to their health status.

The other options listed do not align with the goals of the ACA. The law specifically worked to eliminate practices like rescinding coverage due to application errors, imposing annual or lifetime dollar limits on essential benefits, which were common before the ACA and often left patients vulnerable to high out-of-pocket costs. Thus, the ACA's commitment to continuous coverage for those with pre-existing conditions represents a pivotal shift toward more equitable healthcare access.