You need to report your anticipated income for the entire year.
Obamacare mandates that your annual income determines the amount that you must pay for health insurance. You should be able to get an estimate of your Social Security income from documents they have sent you of by logging into the SSA.gov web site. Add that to your income for the next six months, and report that total to the insurance agent who is helping you.
When you file your 2017 taxes, Form 88962 will reconcile your actual income for the year with the amount you paid for your insurance to determine whether you paid the correct amount.
