I was eligible for, but not receive, the third stimulus check. I was given an amount I should have gotten. I tried to claim it on my return, but wasn't given the option.

[rjs]

If you are not asked about the third stimulus payment, it might be because your AGI (Form 1040 line 11) is above the phase-out range for the Recovery Rebate Credit for your filing status. The AGI cutoff is $80,000 for single or married filing separately, $120,000 for head of household, and $160,000 for married filing jointly or qualifying widow(er). If your AGI is above the cutoff, you are not eligible for the Recovery Rebate Credit. TurboTax will skip the topic and will not ask about your third stimulus payment because it doesn't matter. There will be no entry on Form 1040 line 30.

[VolvoGirl]

How were you given an amount to claim?   Did you get a IRS letter 6475?  

If you didn't get the 3rd Stimulus payment based on your 2020 return (but should have)  and now your 2021 income is too high then sorry you don't qualify for the Recovery Rebate Credit on line 30.  You can't get it.   The 3rd Stimulus payment is really based on your 2021 return.  They just used 2020 to send it out fast.