Your APTC, or subsidy is based upon your household size and income. The income that you list on your Marketplace Application is verified with the income on your tax return. This information in reconciled to ensure your received the accurate amount of subsidy. If you over estimate your income, you could receive a higher tax return, however if you under estimate your income, you could receive a lower income tax return and possibly have to pay back some of the APTC you were given. The Marketplace REQUIRES you to update your information as needed throughout the year by reporting a life change. Your agent can help you report a life change or a Marketplace Representative can assist you with reporting a life change.