A special enrollment period for older Coloradans to sign up for certain Medicare supplement insurance ends June 30. The Colorado Division of Insurance opened up the six-month period after federal changes kept newly eligible people from purchasing some of the supplement policies, which are often sold by private companies to help with costs for copays, deductibles and other things that aren’t covered by original Medicare. People that buy supplemental policies, called Medigap, can do so without having their health or risk evaluated in order to get a plan, said Vincent Plymell, assistant commissioner for the agency.