So do you qualify for the full 2nd Stimulus payment 1,200 BASED on your 2020 AGI? Did you see the screen with 2 boxes to enter what you already get for #1 and #2? You put 2400 in box 1 and enter 0 in box 2?
If Turbo Tax didn't give you the full 1200 on line 30 you must have phased out based on 2020. Is your AGI over 150,000? Generally, if you have adjusted gross income up to $75,000 for individuals and up to $150,000 for married couples filing joint returns and surviving spouses, you will receive the full amount of the recovery rebate. For filers with income above those amounts, the payment amount is reduced.
If your AGI is over the limit, the amount of your payments is reduced by $5 for every $100 over the limit. So, your credit may be a weird amount.
