sounds like they may have signed up accidently or asked for a quote and ended up with a policy, they need to contact healthcare.gov and see if a 1095A was issued to them or anyone listed on their tax return.....IRS thinks a 1095A exists for that return.

Have you received an answer?  I have the same issue.

A binary attachment = a pdf file

I filed a tax return and the taxpayer insurance is through Medical

It was rejected as the IRS internal database indicated that a form 1095-Ahave been or will be received 

and requestedthe 1095-A or include a binary attachmentcontaining "ACA Explanation"

and the taxpayer has no knowledge of all that

a return was rejected  the IRS database shows a form 1095-Ashould have been or will be received

and requested  to providedescription containing  ACA Explanation

@shahinea one of the SSN s listed on that tax return has a 1095A issued to them.  The taxpayer should contact the marketplace (or in your case it looks like they need to contact Covered California) and inquire about the SSNs listed on their return and see if they can obtain a copy for the one involved. Many times they had marketplace insurance for only one or two months before being switched over to MediCal..

In the event that they cannot get this copy, you can attach a pdf to the return and title it ACA Explanation, that should get the return accepted, but probably wont solve the issue, your client can probably expect an IRS letter down the line so they should use this time until then to find this 1095A or get a letter from the marketplace that explicitly states there have been NO 1095As issued to any of the SSNs on the tax return.