When Does Obamacare Start? 
Open Enrollment started October 1st . For plans effective January 1st , you may enroll up until December 31st . This year the Open Enrollment is extended until March 31st . You must obtain a creditable health plan by March 31st or you will be penalized . You may purchase either on or off the exchange . If you qualify for a subsidy you are better off in most cases to purchase on the exchange . 