Complex Medicare advantage choices may overwhelm seniors--especially those with impaired decision making.

The proliferation of Medicare Advantage plans has given Medicare enrollees more choices, but these could be overwhelming for some, especially for those with impaired decision-making capabilities. We analyzed national survey data and linked Medicare enrollment data for the period 2004-07 to examine the effects on enrollment of expanded choices and benefits in the Medicare Advantage program. The availability of more plan options was associated with increased enrollment in Medicare Advantage when elderly Medicare beneficiaries chose from a limited number of plans-for example, fewer than fifteen plans. Enrollment was unchanged or decreased in Medicare Advantage when beneficiaries chose from larger numbers of plans-for example, fifteen to thirty, or more than thirty. Elderly adults with low cognitive function were less responsive to the generosity of available benefits than those with high cognitive function when choosing between traditional Medicare and Medicare Advantage. Simplifying choices in Medicare Advantage could improve beneficiaries' enrollment decisions, strengthen value-based competition among plans, and extend the benefits of choice to seniors with impaired cognition. It could also lower their out-of-pocket costs.