Can I be separated for a DUI?

Yes. You can be separated for Commission of a Serious Offense under paragraph 14-12c, AR 635-200.

The definition of a Serious Offense IAW with paragraph 14-12c, AR 625-200 is:

Commission of a serious military or civil offense, if the specific circumstances of the offense warrant separation and a punitive discharge is, or would be, authorized for the same or a closely related offense under the MCM.

In plain English, if the reason for separation, if taken to courts-martial could result in a Bad Conduct or Dishonorable Discharge, then the offense qualifies as a serious offense.

IAW the Manual for Courts-Martial (MCM), the maximum punishment for Driving Under the Influence is:

DUI causing personal injury: Dishonorable Discharge or Bad Conduct Discharge, 18 months confinement and forfeiture of all pay and allowances.

DUI not causing personal injury: Bad Conduct Discharge, 6 months confinement and forfeiture of all pay and allowance.

Additionally, if a Soldier receives a 2nd DUI within a career, then the following applies IAW ASAP Regulation, paragraph 3-3, AR 600-85:

Any Soldier who is convicted of DWI/DUI two times during their career shall be administratively separated unless retained by the first GO in command who has a judge advocate or legal advisor available.

If you are processed for separation, you must be provided the opportunity to speak with legal counsel at your services Trial Defense Service office.

Disclaimer: I am not an attorney and any views presented are my own and are not to be
interpreted as legal advice. Furthermore, my views do not necessarily
represent the views of DoD or its Components.