How can I claim previous stimulus checks given or see why I wasn’t given one?

If you didn't receive your stimulus payments then you might be able to claim the Recovery Rebate Credit on you 2020 tax return. 

To enter any stimulus payments received in TurboTax, please follow these steps:

1. Log into TurboTax.
2. After entering all your information click "Federal Review" at the top of your screen. 
3. On the screen "Let's make sure you got the right stimulus amount" click "Continue".
4. 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".
5. TurboTax will then calculate the amount of stimulus payment remaining that you are still entitled to get. 
6. Any stimulus amount remaining due to you will show as a credit on line 30 of the 1040.

To check on your stimulus payments from the IRS :IRS Get My Payment

For additional information please see Stimulus FAQ at the end of the TurboTax article.