IRS LTR 12C - Form 8962 requested for non-dependent child

Some background: I prepare the taxes for my three children, two of which are under 25 and able to still be covered on our family insurance plan. I had COBRA coverage through August and then purchased a plan through the Exchange for Sept - Dec., covering my wife and I, plus our two children who are under 25. I mistakenly assumed that both would still qualify as tax dependents on my tax return, so I must have indicated that when I completed the calculation for Advance Premium Credit (APC). When I completed my tax return, I found that only my younger daughter still qualified as a dependent, so I ended up with just 3 for calculation of my eligible premium credit, resulting in my having to pay back a portion of that premium when I filed my taxes. I did also list my son, who is 24, as being covered on the plan when I filed, since he was listed on my 1095-A.

 

When I filed for my son, I did not include the Form 8962, since he did not pay premiums nor receive the APC. Those flowed through my tax return since I paid the premiums. But now after filing his 2018 return, he has received IRS LTR 12C requesting him to complete and submit Form 8962 and a copy of his Form 1095-A.

 

I am unclear how to complete and file this Form for him, since he did not pay any premiums nor receive the credit. As I noted, I already had to pay back the portion of the APC when I completed my return (as I could only claim 3 dependents vs the 4 assumed when I signed up for the policy through the Exchange), so that should not be the issue with his. Can you direct me how to complete this form for my son, so that we can respond to the IRS with the requested information within their timeline?  If you need any additional information, please let me know.  Thank you in advance!