Van Hollen: Doc fix biggest hurdle in getting extenders through the Senate

"That is something the Senate has been talking about, but no decisions have been made," Van Hollen said.

Van Hollen is the Assistant to Speaker Nancy Pelosi (D-Calif.) and sits on the tax-writing Ways and Means Committee that is charged with drafting the extender bill. Rep. Richard Neal (D-Mass.) also sits on Ways and Means and favors a five-year doc fix. 

"That sounds reasonable to me," he told reporters. 

Neal refused to comment on whether carried interest was causing support problems in the Senate. The provision ultimately taxes compensation designated as "carried interest" at ordinary income rates. Several senators have expressed concern over the measure, saying the tax increase would have negative consequences on the economy. 

Some senators seek to strike the carried interest provision from the bill. But Van Hollen said it was "premature" to say if such talk was gaining ground in the House.