Filed 2019 return as married jointly.Me &kid has SSN but my wife doesn't but has ITIN.She is about to get SSN in 4 mon Can i get stimulus check payment when file 2020 tax

Possibly. This is still an uncertain situation, but to the best of my understanding, the stimulus payment is technically an advance payment of a new credit that will be on the 2020 tax return. The current payment is based on previous information so that it gets to you faster. Then, the credit will be recalculated on next year’s tax return, and if you are owed more than you receive now, the extra will be added to your next refund.

when the SSN is assigned, be sure to send a letter to the IRS with copies of the ITIN and SSN information, so the IRS can connect the two sets of records. Use the address in question 12 of this FAQ.

https://www.irs.gov/individuals/itin-expiration-faqs

you probably will not be able to e-file in 2020, since your spouse will be using the new SSN for the first time. That’s OK, just expect that you will have to print and mail your tax returns next season.