Final answer:
The Health Insurance Portability and Accountability Act (HIPAA) ensures that Bill won't be denied coverage when switching health plans, providing protections for individuals moving between insurance plans.
Step-by-step explanation:
The federal law that ensures Bill won't be denied coverage when switching health plans is the Health Insurance Portability and Accountability Act (HIPAA). Passed into law in 1996, HIPAA provides protections for individuals moving between health insurance plans, ensuring that they are not denied coverage due to pre-existing conditions or other factors.
Furthermore, HIPAA sets standards for the protection of patient information, requiring businesses like insurance companies and healthcare providers to maintain strict confidentiality. The Affordable Care Act (ACA), also known as Obamacare, brought significant changes to the healthcare system, including coverage for those with pre-existing conditions and the individual mandate, but it is HIPAA that specifically focuses on the continuity of coverage in the context of changing health plans.