It’s common for income to fluctuate, particularly if you are self-employed, perform seasonal work, or have multiple jobs. To achieve the most accurate premium tax credit amount, you should report income changes to the health insurance marketplace within 30 days. For plan years 2021 and 2022, there is no income limit for premium tax credits, so you won’t lose eligibility for premium tax credits if you underestimated your income, but you may need to pay back some or all of the premium tax credit you received if your actual income is higher. To avoid having to pay back any premium tax credits, you could consider waiting until you file your taxes to take all or a portion of the premium tax credit on your tax return instead of receiving advance payments. (Questions and Answers on the Premium Tax Credit, 26 C.F.R. § 1.36B-4; 45 C.F.R. § 155.340).