For a linear time-variable plant which can be decoupled by state variable feedback, the problem of decoupling by output feedback is discussed. The problem is solved by considering the decoupling problem for a system composed of a compensator in cascade with the plant. The use of the compensator allows decoupling by feedback of the output and its time derivatives. For a special class of compensators, the decoupling can be achieved using only output feedback. Although not of minimal dimension, the compensators used in this paper have the advantage of applicability under very general conditions.