What do I do if my second stimulus check was not the right amount?

[stockpa2018]

We had a baby early 2021 and it was not included in the second or third stimulus checks

[DoninGA]

A child born in 2021 was not eligible for the second stimulus. 

The child is eligible for the 3rd stimulus payment on the 2021 tax return.  The Recovery Rebate Credit of $1,400 on the Form 1040 Line 30 will be entered provided you have completed the tax return and answered the question about receiving the stimulus payment.

[stockpa2018]

I am sorry he was born early 2020 and the second stimulus paid out in early 2021 did not include him.  

[DoninGA]

---

@stockpa2018 wrote:

I am sorry he was born early 2020 and the second stimulus paid out in early 2021 did not include him.  

---

Then when you filed your 2020 tax return you were asked about the stimulus you received. If you answered the question, then the child would have been eligible for the Recovery Rebate Credit of $600.  Look at your 2020 federal tax return Form 1040 Line 30 to see if the credit was entered.