премия за выслугу лет или премия в рамках долгосрочного стимулирования (Long Term Incentive Plan) ??

The income tax on compensation received in one year for ser- vices performed over a period of several years (for example, a ***long-term bonus or termination pay) is calculated by reference to a special formula
(текст - перевод с немецкого)

спасибо