"If you don't want to claim your child as a dependent, delete them from your return. But that does not make them eligible for a stimulus check. "
But, under the CARES Act, if he is claimed (or can be claimed) as a dependent on someone else’s return he cannot receive a stimulus check, in 2020. If he was claimed (or can be claimed) as a dependent for 2019, but will not be for 2020, he will most likely get the stimulus in 2021.
"In essence, the stimulus check acts as an advance of your 2020 income tax refund. This means when you prepare your 2020 income tax return, there will be a line to include the section 6428 credit. The credit on your 2020 return is subtracted by any amount received as a stimulus check in 2020. If the amount you received as a stimulus check is less than the credit you are due, the difference will be included as part of your 2020 refund. If you have been overpaid by receiving the stimulus check, however, you will not be required to return any excess amount".
