I'm referring mainly to California drug cases and that procedure. In a deferred entry of judgment, covered under Penal Code section 1000, a defendant enters a plea of guilty initially. Then, "judgment" (aka sentencing) is deferred for 18 months. The defendant has to attend and complete a drug education & awareness program. After the plea of guilty, the defendant is typically ordered to return to court within 2 weeks to show proof they've enrolled in the class. Six months from the date of the guilty plea, they must return to court and show completion of the classes, negative drug test(s) and have paid a court administrative fee. Then, 18 months from the original plea, they again return to court. Now, after 18 months, if they've completed the classes, paid their fees AND remained free from any criminal conviction (aside from minor traffic offenses), they are entitled to have their case dismissed. A dismissal pursuant to Penal Code section 1000 is rather powerful. A person is legally entitled to say they have no convictions. They can even say they have never been arrested for the offense. It does stay on their record though, so law enforcement can know if a person has been through the program. It's a one-shot deal that you cannot do every drug arrest.