Gap In Coverage Due to Insurer Error?

My kids lost their medical insurance in 2014 because Social Services said they never received my reinstatement paperwork which I mailed to them. When I called to get them coverage they said they no longer offered medical assistance through social services and that I had to enroll for ObamaCare. I contacted my employer health care team to try to get my children on my plan through work. Today I spoke with a rep from Maryland Health Connection who said I could pay $64 a month for both children to be covered. I want to sign them up for it but I am concerned what is going to happen to me because they went without insurance from Sept. 2014 until April 1st, 2015. Can I receive an exemption for those months?