This is unclear.  So far, the federal government has not established a clear appeals process for problems that arise under the rule that permits insurers to refuse to renew Marketplace coverage for nonpayment.  It is important that you sign up for coverage before the end of Open Enrollment.  At this point, options to consider include:

• Ask your insurer to reconsider. Be sure to present your cancelled check or other proof that you paid.
• Report this problem to the Marketplace and to your state insurance regulator and ask their help resolving the problem
• Review Marketplace plan options offered by any other insurers and consider signing up for one of those if you can’t get this problem resolved before 3:00 am ET on December 18.