With 2018 rerurns will not qualify for stimulus. But, in 2019 my wife got SSN. So, when I file for 2019 taxes can I claim for Stimulus amount?
Yes, however, there may be a delay in processing the stimulus payment with the other taxpayers to process. The stimulus is not claimed on the 2019 return.
File the 2019 tax return as soon as possible with your wife's SSN. If you do not receive the economic stimulus payment now, and are eligible, then this will be corrected when the 2020 tax return is filed, due April 15, 2021.
In the meantime, you can visit the following links for the most recent updates: