There are different severities of Stuttering/Stammering and if it affects a life event then yes, it is a disability. If not, then there are different speech therapies, modalities, treatment, etc... My stutter was caused by a traumatic dog attack at the age of 5. During this dog attack, the dog jumped on me and my head hit the hard concrete. I couldn't speak for almost a year and when I could, I had a severe stutter. I went from 0% fluency to 80% now. I've had 20 years of speech therapy, hypnosis and some voodoo (I talk about this often in my podcast). I know many people don't want to hear this but once I accepted it, embraced it, and no longer cared what people thought about my stutter, life became increasingly better. Don't get me wrong, I still have challenging days but I practice mindful meditation and I just don't pay much attention to my stutter. I have learned to become more present in my conversations.