washington u.s. federal program pay elderly americans hospital bill exhaust reserve 2028 two years sooner last year estimate trustees program say wednesday spend growth remain within forecast medicare program provide health coverage 55 million old well disable people say project growth rate per capita spend exceed target put aside need program regulator center medicaid medicare service establish save target initiate mandatory spend cut annual financial report say government would need immediately set independent payment advisory board make proposals cut say drug stock gain release report wednesday nasdaq biotechnology index 2.5 percent lose grind ahead report release wall street analysts worry mandatory save clause trigger new board might try implement cut prescription drug price hit trigger good news healthcare investors sanford bernstein analyst timothy anderson write research note annual financial review trustees also say combine social security disability trust fund reserve estimate run 2034 projection last year medicare spend 2015 total 647.6 billion medicare program trust fund hospital care still schedule sufficient fund 11 years long estimate give affordable care act pass trustees say trustees put short timeline change estimate income cost particularly near term depletion fund available medicare social security mean program would suddenly stop current rate payroll tax collections medicare would able cover 87 percent cost 2028. would fall 79 percent 2043 gradually increase social security would able pay three-quarters schedule benefit 2034 2090 trustees say medicare program spend within target rate trustees