If I am convicted at a court-martial of sexual assault, do I have to register as a sex offender?

Yes. In fact, effective 28 June 2012 the UCMJ amended its sexual assault statute yet again and created even more types of offenses to charge military members and make them registered sex offenders. One of the major expansions of Article 120 is that now if the complaining witness alleges that she or he was touched in a sexual or degrading manner ON ANY PART OF THEIR BODY, and you are convicted, you will have to register as a sexual offender. Formerly, the law stated that only if certain body parts were touched, such as the breast, buttocks, inner thigh, etc., but under these most recent changes, even the arm, back, or ear could technically qualify.