I'm sure that the Marketplace people understand that incomes change, and they have procedures to make adjustments for changes in income. As xmasbaby0 said, you have to talk to them about it.
I know that they have procedures to make adjustments if your income goes up. If you get a reduced monthly payment and then you get a new job, be sure to tell the Marketplace that your income has increased, and cancel your Marketplace insurance when your new insurance starts. A lot of people get burned on their tax return because they didn't tell the Marketplace when their income increased. They continued to get a big subsidy (premium tax credit) for their insurance based on low income, and they have to pay a lot of it back when they file their tax return.
