There is no easy or hard-and-fast answer: it depends on the extent of the stutter and the degree to which it substantially interferes with a major life activity (i.e. communication). A minor stutter would not be a disability, any more than being nearsighted and needing glasses is a disability--the effect is not significant enough. A major stutter that makes talking almost impossible, like significant blindness, would be a disability, since the impact is so great. Where the exact line is between disability and not a disability is not easily determined. However, there is no penalty for applying in good faith for benefits, even if you are ultimately turned down; we would therefore encourage you to contact the agency, make the application, and see what happens.