If I earn more than my income estimate while on a Marketplace plan, do I have to pay the government back?

When you file your tax return for the year in which you were insured, the IRS will compare the income estimate with your actual adjusted gross income. If your actual income is higher than your estimate, you’ll pay back the IRS the difference in what subsidy you did receive vs. what subsidy you should have received. The same goes if you come in lower than your estimate; if you come in lower, the IRS will likely owe you money back, as you should have received a larger subsidy than you actually did. The point is the IRS will even it up to exactly what it should be; as they always do.