11550(a) is being under the influence of a controlled substance. It is a misdemeanor. There are different possible sentences. If the person charged is eligible, they may be allowed to complete PC 1000 (DEJ) which would require drug treatment and result in a dismissal after a certain period. Additionally, Prop 36 is also a possibility. Prop 36 would require drug treatment for a much longer period and other requirements before a dismissal is granted. If ineligible for those options, the law mandates a 90 day jail minimum for a conviction of 11550(a).
An 11550 is a charge that is very conducive to trial defense because there are usually difficulties in proving that someone was under the influence of one of the listed substances. If the person doesn't want to go trial and they are eligible, they can do deferred entry of judgment, which will result in the case being dismissed after a short treatment program. If they lose at trial, they can still do prop. 36. Or they will do either ninety days in jail or in drug treatment.
HS11550(a) is under the influence of a controlled substance. First time offenders usually qualify for pc 1000 or prop 36 which avoids jail time and has otheer benefits. 90 days is a typical sentence if they don't want to do the treatment programs but as Mr. Pullman stated these case can be very favorable for the defense depending on the evidence.