The dependent needs file an amended return to change their status to, they CAN be claimed as a dependent. To not file the amended return would be tax fraud, plain and simple. An amended return can not be e-filed. The IRS says so. An amended return has to be printed, signed and mailed to the IRS.
As for your return, since your dependent incorrectly filed already, the IRS computers already have their SSN marked as "claimed" for the tax year. When your dependent amends their return that will *NOT* change the status of their SSN in the IRS computers. So you have *NO* *CHOICE* but to print, sign and mail your return to the IRS. You will *NOT* be able to e-file your 2019 tax return. Not ever.
Thw things going on here that will delay any refund you may be due.
1) because of the pandemic shutdown the IRS is *NOT* processing mailed returns of any type at this time and they have *NOT* given even the slightest hint of when they will start doing so.
2) For your son, amended returns can take anywhere from 8-12 weeks to process since they have to be processed by hand, by a human. But due to item 1) above, there's no telling when that will actually happen.
Now the IRS has announced that "in the near future" they will implement an ability to e-file amended returns. But again, because of item 1) above, the definition of "near future" is questionable and it's a good bet that e-filing a 2019 amended return *will* *not* *happen* most likely.
https://www.irs.gov/newsroom/irs-announces-form-1040-x-electronic-filing-options-coming-this-summer-...
