Given vectors x and ｙ in a Hilbert space, an interpolating operator is a bounded operator T such that Tx=y. In this paper the following is proved: Let $cal{L}$ be a subspace lattice on a Hilbert space $cal{H}$. Let x and ｙ be vectors in $cal{H}$ and let $P_x$, be the projection onto sp(x). If $P_xE=EP_x$ for each $ E in cal{L}$ then the following are equivalent. (1) There exists an operator A in Alg(equation omitted) such that Ax=y, Af = 0 for all f in ($sp(x)^perp$) and $A=-A^ast$. (2) (equation omitted)