Final answer:
The ACA did not require insurers to require individuals to have health insurance or pay a penalty; instead, it imposed this requirement on individuals. Other ACA mandates for insurers included covering pre-existing conditions, offering essential health benefits, and extending coverage to young adults on their parents' insurance until age 26.
Step-by-step explanation:
By 2014, the ACA (Affordable Care Act) required insurers to do several things, but the one action they were not required to do from the options provided is to 'Require individuals to have health insurance or pay a penalty.' This requirement, known as the individual mandate, actually tasked individuals with obtaining health insurance coverage or facing a penalty. It was a means to ensure that there would be enough healthy individuals in the insurance pools to help balance the costs for those who are high-risk and require more medical attention.
The ACA did require insurers to provide coverage for pre-existing conditions, offer essential health benefits, and allow young adults to stay on their parents' insurance until age 26. These changes aimed to increase coverage for the uninsured, provide comprehensive coverage, and extend the ability for young adults to receive health insurance during a pivotal transition period in their lives.