The life expectancy and retirement of a client or their spouse is a value that can be specified on a per scenario basis. Each scenario can be set to a different value.
To set this value you must open a scenario and browse to the Worksheets -> Client Data -> General Information Tab.
From here you can review or set the life expectancy for the client and spouse in the Personal Information section.
NOTE: Changing the life expectancy in one scenario does not update all existing scenarios.