Bolden wrote (emphasis ours):

Reductions from the FY 2016 request for Commercial Crew proposed in the House and Senate FY 2016 Commerce, Justice, Science, and Related Agencies appropriations bills would result in NASA's inability to fund several planned CCtCap milestones in FY 2016 and would likely result in funds running out for both contractors during the spring/summer of FY 2016. If this occurs, the existing fixed-price CCtCap contracts may need to be renegotiated, likely resulting in further schedule slippage and increased cost.

Those "CCtCap or Commercial Crew Transportation Capability contracts" are with private space companies Boeing and SpaceX, which are developing vehicles that can carry NASA's astronauts to the ISS. Both of them are on track to end the agency's dependence on Russian Soyuz spacecraft by 2017, with test flights planned before then. Since only the lack of money could hinder their progress, Bolden made sure to emphasize that "[t]he safe, reliable, and cost-effective solutions being developed here at home will allow for more astronauts to conduct research aboard the space station, enable new jobs and ensure US leadership in spaceflight this century."

[Image credit: NASA HQ PHOTO/Flickr]