I know this message is old, but can you please tell me how long it took to get the error corrected. The IRS (the IRS says it is actually the Marketplace) did the same thing to me this year and like you, I did not have Marketplace insurance nor did my dependents (they both have Medicaid). The IRS sent the 12C letter on March 6, and I responded on March 11. The IRS said that it could take up to 8 weeks to process. I was just curious as to whether you were able to resolve your issue, and if so, how long it took. Thank you.
