There is no minimum amount of income that must be earned in order to claim the child tax credit. Rather, there is a maximum amount that would prevent the credit from being taken. You are entitled to a credit of up to $1,000 per child assuming all the tests are met (see link below). Depending on your situation, the credit may be refundable, meaning that even if you don't need the full $1,000 to reduce your tax liability to zero, the IRS may give you the remainder back as a refund. This is where your question about income levels comes into play. The amount of the credit that is refundable is the smaller of the unused portion of the credit or 15% of your earned income over $3,000.
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