If you want coverage that meets minimum ACA standards, you have to sign up during the annual open enrollment period unless you qualify for a special enrollment period. For 2024 coverage, the open enrollment period for most Marketplaces begins November 1, 2023 and extends through January 16, 2024. Some states may have different open enrollment periods, so check with your Marketplace. Once the open enrollment period is over, most individuals and families will not be able to enroll in Marketplace health plans until the next open enrollment period. However, if you experience certain changes in circumstances during the year, you may have a special 60-day opportunity to enroll in Marketplace health plans, through a special enrollment period. American Indians, and Alaska Natives and in most states, individuals with incomes below 150 percent of the federal poverty level, can enroll throughout the year. (45 C.F.R. §§ 155.410, 155.420; HealthCare.gov, Health coverage for American Indians & Alaska Natives.)
Individuals and families buying non-group coverage on their own, outside of the Marketplace, can also only enroll in coverage during open enrollment periods and special enrollment opportunities. (45 C.F.R. § 147.104.)