Many clients and potential clients of the law firm inquire about the impact expunging a criminal conviction will have on potential license discipline.  The answer is that the expungement, while not a cure-all, is an excellent piece of evidence of rehabilitation that must be considered by the administrative law judge and licensing agency in imposing license discipline.
Under Penal Code section 1230.4, a criminal defendant who has fulfilled the conditions of probation, under some circumstances, may change a plea to not guilty or the court may set aside the verdict and dismiss the criminal case against the defendant.  This is sometimes referred to as having the conviction “expunged,” although the proceeding results in a dismissal of the charges and not a true expungement.
Generally the dismissal of a conviction under Penal Code section 1203.4 does not prevent a licensing agency from bringing a disciplinary action based on the conviction.  For example, Business and Professions Code section 490(c) explicitly provides for agency authority to discipline notwithstanding expungement. (See also Krain v. Medical Bd. (1999) 71 Cal.App.4th 1416, 1420 (agency may take disciplinary action based on expunged conviction unless statute provides otherwise).)
However, expungement is considered by almost all licensing agencies as a form of proof of rehabilitation.  It demonstrates to the agency your appreciation of your prior wrongful conduct and you taking the necessary steps to not only complete the terms of your criminal punishment, but the extra step of clearing your record.  And while expungement itself does not automatically mean the licensee is rehabilitated, (see e.g. Opdyk v. California Horse Racing Bd. (1995) 34 Cal.App.4th 1826 (mere fact of expungement does not automatically make licensee rehabilitated)), a number of agencies are required by statute to “give special consideration” to applicants whose convictions have been expunged.  Yet, even more, list expungement of convictions as one of several mitigating factors or evidence of rehabilitation to consider when creating the appropriate discipline.
Thus, to answer so many of our clients’ and potential clients’ question, yes, expungement is something worthwhile to pursue and achieve.  However, please make sure that you go into the process with eyes wide open, knowing that the expungement itself will not preserve your license alone.