You should not owe a penalty for not having insurance. What you are seeing is probably a repayment of part of the Premium Tax Credit.
When you entered information about your healthcare coverage, the program asks you to enter the months that you had coverage. You should check all months that you had insurance coverage, not just the months listed on your form 1095-A. Click on the attached image for a screen shot of the screen that begins the interview.
If you entered all those months and you are still being charged a penalty, this is what is happening:
When you purchase insurance on the Marketplace, you have to provide an estimate of your earnings for 2016. You then get a Premium Tax Credit, or subsidy, based upon that estimate. Since you weren't yet married, and you only needed coverage for yourself, your estimate would have been way off.
Tax year 2016 is now over, and your actual income is available. According to the rules of Obamacare, your total 2016 family income and family size will be compared with what you paid for your months of Marketplace coverage. If you paid too much, you will get a refund; if you paid too little, you will be asked to make up the difference.
You can find
information about health insurance coverage penalties here.
