This has been asked a number of times in the last week. No clear answer.

I believe that some are recommending the client contact the clearinghouse and ask for a copy of 1095-A even if they are "sure" they didn't have any.

It sounds like you have a client who may have been on parent's insurance.

I don't think  that would be something they are "supposed to have to report", but who knows how screwed up the IRS has the system this year.