Premiums are allowed to vary by enrollee age .
Those for the oldest enrollees ( age 45 -- 64 , average expenses $5,542 ) can only be three times as large as those for adults 18 -- 24 ( $1,836 ) .
Premiums are allowed to vary by enrollee age , but those for the oldest enrollees ( age 45 -- 64 , average expenses $5,542 ) can only be three times as large as those for adults 18 -- 24 ( $1,836 ) .