If you are currently enrolled in a plan on the health insurance Marketplace, you are eligible for a special enrollment period so long as you do so within 60 days of your change in status (although there may be an extension for exceptional circumstances). By January 1, 2024, the Marketplace must allow you to change to a plan at any metal level.
Note: If you want to buy health insurance outside the health insurance Marketplace, you will need to wait until the open enrollment period to buy a plan that provides the consumer protections required by the Affordable Care Act. (45 C.F.R. § 155.420(a), (d)).