Definitions for "Top Heavy Plan"
A plan in which more than 60% of its value is for the benefit of  key empolyees, including owners and officers. Additional requirements apply to top-heavy plans, such as more rapid vesting schedules and minmum contributions for plan participants who are not key employees.
For plan years beginning in 1984, a plan that primarily benefits key employees is considered top-heavy and qualifies for favorable tax treatment only if, in addition to the regular requirements, it meets several special requirements
A plan in which 60 percent of account balances (both vested and non-vested) are held by certain highly compensated employees.