@tccutler
Your transcripts have nothing to do with the recovery rebate, unless you filed for a rebate in 2020 and it was not paid, or it was reduced. The fact that your 2017 through 2019 transcripts might not show the child has no effect on 2020.
So are we trying to fix 2017 through 2020 or are we only trying to fix 2020?
Then if we are only trying to fix 2020:
1. How many dependents did you claim on your 2020 tax return who were age 16 or less on December 31, 2020?
2. How much did you receive in round 1 and round 2 of the stimulus during 2020 and early 2021?
3. Was your tax refund reduced from what you claimed on your 2020 return when you filed it?
It may also be important here to emphasize that the stimulus rebate calculated on the tax return is based on the number of dependents you claim and not their identity. For example, consider a family with a 17-year-old child and a newborn. They may have been paid a stimulus payment that reflected one child, because they had a qualifying child in 2019. On the 2020 tax return they are adding a newborn dependent, but the 17 year old has aged out of eligibility. Because they received a stimulus payment for one eligible dependent, and they are claiming one eligible dependent on their 2020 tax return, they will not receive an additional rebate, even though the identity of the dependents has changed.
The round one stimulus payment, the round two stimulus payment, and the economic recovery rebate on the 2020 tax return are all based on qualifying dependents who must be age 16 or less at the time.
