What is the premium tax credit for ACA marketplace health insurance?

The premium tax credit lowers the cost of health insurance bought through the ACA marketplace (healthcare.gov or a state exchange). It's based on your estimated household income and the cost of a benchmark plan, and most people take it in advance as a monthly subsidy that reduces their premium directly. At tax time you reconcile the advance credit against your actual income on Form 8962; if you earned more than expected you may repay some, and if you earned less you may get more back. Through enhanced rules in effect for 2025, the credit can reach households well above the old 400%-of-poverty ceiling, capping benchmark premiums at a percentage of income. Because it's income-based, managing your AGI, through retirement contributions or HSA deposits, can increase the subsidy. Self-employed people in particular should pay close attention.