Aetna Medicare Signature (PPO) H5521-250 and H5521-207 are not offered in 19 Colorado counties in 2027

Your deadlines and rights when a plan ends or leaves your county

You can use the Annual Enrollment Period, October 15 through December 7, to choose your 2027 coverage. When your plan is not renewed for 2027, whether the insurer ends that plan, stops offering it in your county or ends its whole contract with Medicare, you have a Special Enrollment Period from December 8 through the last day of February. Coverage you choose by December 31 starts January 1 with no gap, while coverage you choose in January starts February 1 and coverage you choose in February starts March 1, leaving you on Original Medicare alone until then. If you make no choice, you return to Original Medicare automatically, but for most people drug coverage does not follow: unless you choose a Part D plan you may start the year without it, and if you later join a drug plan after going 63 days or more in a row without creditable drug coverage, a late enrollment penalty is added to your premium for as long as you have Medicare drug coverage, unless you get Extra Help. If you have Extra Help or Medicaid, Medicare may assign you a drug plan automatically, though you can still choose a different one. When your plan ends, you can also have a guaranteed issue right to buy certain Medigap policies with no medical underwriting, from the date you receive your plan's termination notice until 63 days after your coverage ends, but a Medigap policy works only with Original Medicare, and joining another Medicare Advantage plan does not extend that window. If you have Medicaid, insurers generally cannot sell you a Medigap policy. Our guide to a plan ending for 2027 explains each of these in more detail.