You are in the US, right? To be committed you are assessed by a psychologist who makes a recommendation to the judge/magistrate who will then send you to a psychiatric hospital for evaluation by a psychiatrist. If the psychiatrist believes you are a hazard to the well being of yourself or others he communicates that to the judge who will then commit you to a psychiatric hospital for treatment. You will be represented by an attorney when you meet with the judge.

You may have access to some of your medical records but mental illness law is different than medical illness. You will likely not be given some documentation by psychiatrist/psychologist because it is not in the best interest of some people to read this information not knowing how to interpret it. It really has nothing to do with HIPAA. HIPAA protects your records from release to other parties not to yourself.