Regardless of whether you purchase insurance through the exchange or off-exchange, the annual open enrollment window applies. You cannot enroll outside of open enrollment unless you have a qualifying event, such as:

• Marriage;
• Becoming a U.S. citizen;
• Birth or adoption;
• Involuntary loss of other health coverage; or
• Permanent move to an area where new health plans are available (this only applies in most cases if you already had coverage prior to your move).

As of 2016, Healthcare.gov started requiring proof of eligibility for the most common qualifying events. Health insurance carriers also generally require proof of eligibility when people enroll off-exchange during a special enrollment period. If you experience a qualifying event and wish to enroll in a plan during your special enrollment period, be prepared to provide documentation of the qualifying event.