I received the monthly advance payment for health insurance through the marketplace for 9 months but also received unemployment. It is now telling me that my income is too high and I have to repay $9459. Is income based on total or AGI?

Your premium tax credit is based on your modified adjusted gross income (AGI), which means your adjusted gross income plus items of income that are not subject to tax, such as the portion of your social security wages that are not taxed. So, it is more based on your total income than your AGI.