A Social Security trust fund is expected to run short of cash by 2033, according to new estimates, which would potentially reduce benefits to millions of Americans who depend on the program. Kevin Dietsch/Getty ImagesThe Social Security program is expected to run short of cash to pay promised benefits in about ten years, while a key trust fund for Medicare will run out of funds by 2031, according to new forecasts issued Friday by trustees of both programs. 7 workers paying into the system for each person drawing Social Security benefits