Medicare beneficiaries have until Dec. 7 to take advantage of an annual open enrollment period.

For retirees who rely on prescription drugs, experts say it’s a good time to evaluate the cost of those treatments for next year.

Medicare’s annual open enrollment lets beneficiaries change their private Medicare Advantage plans, which may include drug coverage, or change Medicare Part D prescription plans if they have original Medicare, including Parts A and B for hospital and medical insurance. Beneficiaries may also switch from Medicare Original to Medicare Advantage or vice versa.

While select opportunities to change Medicare coverage may come up at other times of the year, this is when beneficiaries “have the most flexibility in the entire year,” according to Ryan Ramsey, associate director at the National Council on Aging, a national advocacy organization for older adults.

Stories for investors who are retired or are approaching retirement, and are interested in creating and managing a steady stream of income: