Final answer:
A pre-existing condition is a health issue for which the insured has been treated in the past, such as chronic diseases or previous illnesses. Before the ACA, these conditions were often grounds for insurance denial or higher premiums, which contributed to the high number of uninsured Americans. The ACA changed this by mandating coverage for pre-existing conditions and working to reduce the number of uninsured.
Step-by-step explanation:
A pre-existing condition is a health issue for which the insured has been treated in the past. This includes previous illnesses or chronic diseases that the individual had before the start of a new insurance plan. Prior to the implementation of the Patient Protection and Affordable Care Act (ACA) or Obamacare, insurance companies could deny coverage or charge higher premiums to individuals with pre-existing conditions, contributing to the high number of uninsured or underinsured individuals. The ACA mandated that coverage could no longer be denied to individuals with pre-existing conditions, significantly impacting healthcare access and affordability in the United States.
The high cost of healthcare and the practices of insurance companies led to increasing numbers of people without insurance. This was exacerbated by the fact that not all employers offer insurance, especially in retail or for part-time workers. The uninsured often resort to using emergency rooms for treatment, which is the most expensive form of healthcare, thus contributing to the overall rise in healthcare costs. The ACA, with its introduction, brought about significant changes, ensuring that people with pre-existing conditions could receive insurance coverage and attempt to correct the imbalances which had led to high levels of uninsured individuals.