http://www.ssa.gov/planners/credits.html http://www.ssa.gov/planners/credits.html#&a0=1 http://www.ssa.gov/planners/credits.html#&a0=2 work credits http://www.ssa.gov/planners/credits.html#a0=2 http://www.ssa.gov/planners/credits.html#&a0=2 http://www.ssa.gov/planners/credits.html#&a0=0 number of work credits needed