@mikeasmel
For the first and second stimulus payment, when you have completed your federal tax return and are about to go to the state module, there is a federal review page, where any last or missed federal items are brought to your attention. You can also access this directly by clicking the federal tab, and then clicking “review”, which should be to the right of “income” and “deductions and credits”.
If you are married filing jointly, TurboTax will ask if you received the full amount for your situation, which is $2400 in round 1 and $1200 in round 2. If you check the box for “no”, TurboTax will ask again “are you sure?” to make sure that your figures are accurate, and then you will be given a place to enter the amount that you did receive. If you tell TurboTax that you received $2400 in round 1 and $600 in round 2, and if your income is below the threshold of $150,000, then TurboTax should add the other $600 to line 30 of your tax return as the recovery rebate.
Note that if the IRS issued a payment, and you did not receive it for some reason, such as incorrect banking information, you can’t claim the rebate on your tax return, you must trace the missing payment. The IRS might have issued $600 to one of you and not the other, or it might’ve issued $600 separately to each of you, and one of the payments went missing. If you claim a rebate and the IRS thinks it already paid one, your refund will be delayed and you won’t get the money. To check what the IRS thinks they issued, each spouse needs to log into their online account—each spouse has a separate account in their name even though you file a joint return.
https://www.irs.gov/payments/view-your-tax-account
Also note that any taxpayer who did not receive the correct amount of the third stimulus payment will be eligible to claim a recovery rebate on their 2021 tax return, although you clarified that this is not the situation for you.
