National Stuttering Association (NSA)he National Stuttering Association (NSA) provides support, friendship, and information to the stuttering community. The NSA® is the largest non-profit organization in the world dedicated to bringing hope and empowerment to children and adults who stutter, their families, and professionals, through support, education, advocacy, and research. Our vision is to build on our position as the preeminent organization for supporting people who stutter.