NEW YORK -- As millions are receiving their second round of stimulus checks, some eligible Americans won't and need to claim the $600 on their 2020 tax returns, according to the Internal Revenue Service. Funds were officially available Monday and will continue to go out through mid-January, according to the IRS. Yet people have reported a range of problems with receiving these funds, from cryptic messages on the "Get My Payment" tool to checks being sent to the incorrect bank accounts. The IRS said some of these taxpayers will not receive a second Economic Impact Payment and instead, they need to claim the Recovery Rebate Credit on their 2020 tax returns.