Short-term health insurance — for gap coverage, with caveats.

ACA plans must cover the 10 essential health benefits (preventive care, prescription drugs, mental health, etc.) and can't deny you for pre-existing conditions. Short-term plans are cheaper but exclude most pre-existing conditions and many essential benefits. Short-term is for gap coverage; ACA is for ongoing protection.

If your household income is between 100% and 400% of the Federal Poverty Level — and in some cases above 400% — you likely qualify for a premium tax credit. The marketplace calculates this automatically when you apply. Many people qualify for a $0/mo plan.

Open Enrollment for ACA marketplace runs November 1 to January 15 in most states. Outside of that, you need a Qualifying Life Event (job loss, marriage, baby, move) to enroll. Medicare has its own enrollment windows. Short-term plans can be bought year-round.

Part A: hospital coverage (usually free if you paid Medicare taxes). Part B: doctor visits + outpatient (monthly premium). Part C: Medicare Advantage — bundles A+B+often D through a private insurer. Part D: prescription drug coverage. Most people pair Original Medicare (A+B) with a Part D plan and a Medigap supplement, or choose a Medicare Advantage (Part C) plan instead.

The federal mandate penalty was reduced to $0 in 2019, so federally you're not penalized for going uninsured. However, California, DC, Massachusetts, New Jersey, and Rhode Island still have state-level mandates with penalties. Even without a penalty, going without coverage exposes you to catastrophic medical bills.