To be eligible for the credit you need to be a U.S. citizen or U.S. resident alien in 2020 and have a Social Security number that is valid for employment.
You cannot be claimed as a dependent by someone else to be eligible.
Your credit amount will be reduced if your 2020 adjusted gross income (AGI) is more than:
$150,000 if married and filing a joint return or filing as a qualifying widow or widower
$112,500 if filing as head of household or
$75,000 for eligible individuals filing as a single or as married filing separately.
Your payment will be reduced by 5% of the amount by which your AGI exceeds the applicable threshold above. (IRS FAQ Recovery Rebate Credit )
To claim the credit in TurboTax, please follow these steps:
Log into TurboTax.
After entering all your information click "Federal Review" at the top of your screen.
On the screen "Let's make sure you got the right stimulus amount" click "Continue".
You will be asked about the amounts of first round and second round stimulus payments you received. If you did not receive a payment enter "0".
TurboTax will then calculate the amount of stimulus payment remaining that you are still entitled to get.
Any stimulus amount remaining due to you will show as a credit on line 30 of the 1040.
Wasn't the missing 600 listed on your 1040 line 30? It should have been. It either adds to your refund or reduces a tax due. Or did you put down you were a dependent in 2020? Did you get the first 1,200?