NASA will operate aboard the International Space Station (ISS) until 2024, but there is no consensus on what do after that year [space.com]. There is some talk of commercializing the station (and a Bigelow Expandable Activity Module [wikipedia.org] is already attached to the ISS):
The United States' ability to send astronauts to Mars in the mid-2030s depends in part on cutting back or ending government funding for the International Space Station (ISS) after 2024, the head of a congressional subcommittee that oversees NASA said Wednesday (March 22). "We ought to be aware that remaining on the ISS [after 2024] will come at a cost," U.S. Rep. Brian Babin, a Texas Republican who chairs the House Science and Technology's Subcommittee on Space, said during a hearing about options and impacts for station operations beyond 2024 [space.com]. "Tax dollars spent on the ISS will not be spent on destinations beyond low Earth orbit, including the moon and Mars," Babin said. "What opportunities will we miss if we maintain the status quo?"
[...] [NASA Associate Administrator Bill] Gerstenmaier, who oversees NASA's human exploration programs, urged Congress to plan a smooth transition from the station to beyond-low-Earth-orbit initiatives, with an eye on preserving U.S. leadership in space, especially with China planning to launch a new space station [space.com] in 2023. [...] Mary Lynne Dittmar, executive director of the Coalition for Deep Space Exploration advocacy group, warned that ending the U.S.' efforts at the station too early could nix budding commercial space companies, some of which might eventually support the station's continued operation as a commercial outpost. "Applications with strong market potential are emerging," Dittmar said. "Abandoning the ISS too soon will most certainly guarantee failure."
[...] While Congress ponders the station's future, NASA should expand its partnerships with private companies, urged Eric Stallmer, president of the Commercial Spaceflight Federation, a Washington, D.C.-based industry association. "The NASA investment[s] in these partnerships are already paying huge dividends," Stallmer said. For example, by partnering with private companies, NASA has been able to cut its costs to fly cargo — and, soon, crew — to the station, compared with what it spent to operate its own fleet of space shuttles [space.com], which cost about $500 million per mission to fly.
Also at The Verge [theverge.com].