Worries about plan cancellations, premium increases and Medicare supplement alternatives top the list of concerns expressed to an online brokerage during the annual enrollment period for Medicare Advantage plans.

Health Plan One, a Shelton, Conn.-based brokerage licensed in all 50 states, reports that seniors also are inquiring about plans’ physician networks, changes to drug formularies and what plans are being introduced or eliminated in their state, according to a statement.

“A year is a long time to wait to make plan changes, particularly in this economic environment,” said Bill Stapleton, president and chief executive officer of Health Plan One.

The annual open-enrollment period runs from November through Dec. 31, during which time seniors can obtain supplemental coverage to their Medicare plan by choosing from a number of Medicare Advantage plan providers, many of which heavily market their services during this time period.