What is Affordable Care Act (ACA)? It was legislated in 2010 to increase health insurance coverage, reduce costs, and implement consumer protections.

It is a service that helps people shop for and enroll in affordable health insurance. The federal government operated Healthcare.gov, while some states run their own exchanges.
California has a program "Covered California" which can be reached at coveredca.com

Health Insurance Marketplace: A central platform (such as healthcare.gov) where individuals can compare and purchase private insurance plans.

Subsidies and tax credits: If your incomes are between 100% and 400% of the federal poverty level, you may be eligible for subsidies and tax credits.

Essential health benefits: All ACA compliant plans must cover ten core areas, including emergency services, prescription drugs, maternity care, and mental health services.

Consumer protections: Insurance companies cannot deny coverage or charge more for pre-existing conditions, nor can they set annual or lifetime limits on essential health benefits.

How is ACA used by people who are planning for retirement?

For example, let’s assume that one of the spouses is planning to retire while the other is not working (otherwise they could have used the working spouse’s health insurance). They can time it such that the retirement is at age 65 or later, apply for Medicare in the initial enrollment period, and avail it later.

If the non-working spouse is younger than 65, ACA could be used to bridge the gap. If the non-working spouse is 65 or older, they could have started their Medicare.

You can go to Covered California Plans (if you are a resident of CA) and shop for plans which suit your needs.

Key Information

As mentioned above health insurance is available through the marketplace. You can also visit your state's health insurance exchange for additional local details. Many states use the federal site, while others have their own dedicated portals accessible via the dropdown on the main page.

Important Enrollment Dates

November 1: Open Enrollment starts - first day you can enroll in, renew, or change health plans.

December 15: Last day to enroll for coverage to start January 1

January 1: Coverage starts for those who enrolled by December 15.

January 15: Open Enrollment ends. After this date, you generally need a Special Enrollment Period (e.g. job loss, moving) to enroll.

Special Note

Since the enrollment ends mid Dec and coverage starts the following Jan, people who retire mid year, have the flexibility to continue same coverage with COBRA so they don't have to spend time and effort, instead do their research. Towards the end of the year, they pick the coverage from plans offered by Medicare