I have schizoaffective do. I am having cognitive issues is Neuropsychological impairment normal? How bad can it get? Should I be tested!?

Not normal. You've had multiple psychiatric hospitalizations and poor concentration for which I'm guessing you take Concerta. Often neuropsych testing - briefer version- is done during a psych. hospitalization. If you've never had testing or it's been more than a few years, neuropsych testing might be clinically useful to your doctor or therapist. Please discuss advisability with them. Hope this helps.
Not normal, but. an expected aspect of schizoaffective disorder. Cognitive problems often improved with overall treatment. You probably don't need separate neuropsychological testing, unless there is a question of a possible other cause for the cognitive problems.