11550 HS Explained: Under the Influence of Drugs in CA

California Health and Safety Code section 11550 makes it a crime to use, or be under the influence of, certain controlled substances unless they were administered by or under the direction of a person licensed to do so. It also sets a separate, more serious offense for being under the influence of specific drugs while in immediate personal possession of a loaded, operable firearm.

This page covers what section 11550 says as published on the California Legislature's official site, what the prosecution has to prove under the state's jury instructions, and the penalties the section sets in each subdivision. It covers California state law only.

Information last verified against primary sources on October 20, 2026. This article has not yet been reviewed by a licensed lawyer.

What 11550 HS says

Section 11550 has seven subdivisions. Subdivisions (a) through (d) cover use and being under the influence, subdivisions (e) and (f) cover the firearm offense, and subdivision (g) addresses deferred entry of judgment and drug court.

11550(a): use or being under the influence

"A person shall not use, or be under the influence of any controlled substance that is (1) specified in subdivision (b), (c), or (e), or paragraph (1) of subdivision (f) of Section 11054, specified in paragraph (14), (15), (21), (22), or (23) of subdivision (d) of Section 11054, specified in subdivision (b) or (c) of Section 11055, or specified in paragraph (1) or (2) of subdivision (d) or in paragraph (3) of subdivision (e) of Section 11055, or (2) a narcotic drug classified in Schedule III, IV, or V, except when administered by or under the direction of a person licensed by the state to dispense, prescribe, or administer controlled substances."

The subdivision adds: "It shall be the burden of the defense to show that it comes within the exception."

Which drugs those schedules include

• Methamphetamine and amphetamine. Section 11055(d) lists "(1) Amphetamine" and "(2) Methamphetamine, its salts, isomers, and salts of its isomers." Section 11550(a) names both paragraphs.
• Heroin. Section 11054(c), the Schedule I opium derivatives, lists "(11) Heroin."
• Cocaine base. Section 11054(f) lists "(1) Cocaine base."
• Cocaine and opiates. Section 11055(b) lists opium and opiates and "(6) Cocaine, except as specified in Section 11054," and section 11055(c) covers opiates.

This page does not list every substance in those schedules. The full lists are in section 11054 and section 11055.

11550(b) and (c): repeat convictions and rehabilitation programs

Subdivision (b)(1) applies to a person convicted under subdivision (a) "when the offense occurred within seven years of that person being convicted of two or more separate violations of that subdivision, and refuses to complete a licensed drug rehabilitation program offered by the court pursuant to subdivision (c)." That person "shall be punished by imprisonment in a county jail for not less than 180 days nor more than one year."

The court cannot excuse the 180-day minimum "unless there are no licensed drug rehabilitation programs reasonably available." Under (b)(2), a program is not reasonably available unless the person is not required to pay more than the court determines the person can reasonably pay.

Subdivision (c)(1) lets the court, "when it would be in the interest of justice," permit a person convicted under subdivision (a) to complete a licensed drug rehabilitation program "in lieu of part or all of the imprisonment in a county jail," and the court may require the person to pay all or part of the program's cost as a condition of sentencing.

11550(d): the $70 fine

In addition to any other fine, the judge "may assess a fine not to exceed seventy dollars ($70)." The court must consider the defendant's ability to pay, and a defendant "shall not be denied probation because of his or her inability to pay" this fine.

11550(e) and (f): under the influence with a loaded firearm

"(e)(1) Notwithstanding subdivisions (a) and (b) or any other law, a person who is unlawfully under the influence of cocaine, cocaine base, heroin, methamphetamine, or phencyclidine while in the immediate personal possession of a loaded, operable firearm is guilty of a public offense punishable by imprisonment in a county jail for not exceeding one year or in state prison."

Under (e)(2), "immediate personal possession" "includes, but is not limited to, the interior passenger compartment of a motor vehicle." Subdivision (f) says a person who violates subdivision (e) "is punishable upon the second and each subsequent conviction by imprisonment in the state prison for two, three, or four years."

11550(g): deferred entry of judgment and drug court

Subdivision (g) says section 11550 does not prevent deferred entry of judgment or participation in a preguilty plea drug court program under Penal Code Chapter 2.5 (commencing with section 1000), unless the person is charged with violating Penal Code section 243(b) or (c).

It adds that a person charged with being under the influence of a substance in section 11054(d)(21), (22), or (23) or section 11055(e)(3), and also charged with violating Penal Code section 243(b) or (c), or charged with a violation of subdivision (e), "shall be ineligible for deferred entry of judgment or a preguilty plea drug court program." This page does not cover the eligibility rules in Penal Code section 1000 and following.

What the prosecution has to prove

California's official jury instruction is CALCRIM No. 2400, "Using or Being Under the Influence of Controlled Substance (Health & Saf. Code, § 11550)," published by the Judicial Council of California (2026 edition). It gives two alternatives. The prosecution must prove either:

• Use. The defendant willfully used the controlled substance, with an optional addition that it was "a short time before" the arrest; or
• Under the influence. The defendant was willfully under the influence of the controlled substance when arrested.

The instruction says "Someone commits an act willfully when he or she does it willingly or on purpose." Its optional definition says a person is under the influence if the person "has taken or used a controlled substance that has appreciably affected the person's nervous system, brain, or muscles or has created in the person a detectable abnormal mental or physical condition."

Where a prescription defense is raised, the instruction says the defendant is not guilty if the defendant had a valid prescription for the substance written by a licensed California physician, dentist, podiatrist, naturopathic doctor, or veterinarian, and that the People must prove beyond a reasonable doubt that the defendant did not have one.

The instruction's bench notes explain how this fits with the statute's sentence putting the burden on the defense: "The defendant need only raise a reasonable doubt about whether his or her use of the drug was lawful because of a valid prescription."

This page summarizes CALCRIM No. 2400 only. It does not cover the jury instruction for the firearm offense in subdivision (e).

Penalties under 11550 HS

Each subdivision states its own punishment.

11550(a). "A person convicted of violating this subdivision is guilty of a misdemeanor and shall be sentenced to serve a term of not more than one year in a county jail. The court may also place a person convicted under this subdivision on probation for a period not to exceed five years." The judge may add a fine of up to $70 under subdivision (d), and under subdivision (c) the court may allow a licensed drug rehabilitation program in place of part or all of the jail time.

11550(b). For a person with two or more separate 11550(a) convictions within seven years who refuses a court-offered licensed drug rehabilitation program, county jail for not less than 180 days and not more than one year.

11550(e). County jail for not more than one year or state prison. Because the text allows either, this is a wobbler, an offense punishable either way. Subdivision (e) does not state a prison term for a first conviction. Penal Code section 18(a), the general rule for an offense declared to be a felony, sets 16 months, two, or three years in state prison "Except in cases where a different punishment is prescribed by any law of this state." Subdivision (e) calls the offense a public offense rather than declaring it a felony, and this page does not state how a court applies section 18(a) to it.

11550(f). For a second or later conviction under subdivision (e), state prison for two, three, or four years.

Section 11550 is not on the list in section 11395(c), the Proposition 36 Treatment-Mandated Felony Act. That list of qualifying prior convictions names sections 11350, 11351, 11351.5, 11352, 11353, 11353.5, 11353.7, 11370.1, 11377, 11378, 11378.5, 11379, 11379.5, 11379.6, 11380, and 11395.

Related sections

• Health and Safety Code section 11377. Possession of methamphetamine and other non-narcotic substances. See our 11377 HS explainer.
• Health and Safety Code section 11350. Possession of heroin, cocaine, and other narcotic-type drugs. See our 11350 HS explainer.
• Health and Safety Code section 11364. Possession of drug paraphernalia. See our 11364 HS explainer.
• Penal Code section 1000. The start of the deferred entry of judgment chapter that subdivision (g) refers to. Official text.
• Penal Code section 19. "Except in cases where a different punishment is prescribed by any law of this state, every offense declared to be a misdemeanor is punishable by imprisonment in the county jail not exceeding six months, or by fine not exceeding one thousand dollars ($1,000), or by both." Section 11550(a) prescribes its own term of up to one year. Official text.

Driving after drug use is a separate subject, covered in our guide to California DUI laws. For how California sorts crimes into felonies and misdemeanors, see California felony and misdemeanor classes. Other statute explainers are in our statutes library.

Legislative history

The official history note for section 11550 reads: "Amended by Stats. 2014, Ch. 819, Sec. 1. (AB 2492) Effective January 1, 2015." The note does not describe what the amendment changed. The text quoted on this page is the version published on the Legislature's site as of October 20, 2026.

What happens after an arrest for 11550 HS

A "11550" on a jail roster or booking sheet is the arresting agency's charge. The prosecutor reviews the case and decides whether to file a 11550 charge, a different charge, or nothing. The first court appearance, the arraignment, is where the filed charges are read.

Our California charge code lookup translates other booking codes, and What Happens After You Get Arrested walks through the steps from booking to arraignment.

Disclaimer

This page explains what California Health and Safety Code section 11550 and the related sections quoted here say, as published on official state sources and checked on October 20, 2026. It is general legal information, not legal advice, and reading it does not create an attorney-client relationship. Options such as rehabilitation programs and deferred entry of judgment depend on the charges and a person's record, so anyone facing a 11550 charge should speak with a criminal defense lawyer licensed in California.

Last updated: October 20, 2026.

Frequently Asked Questions

What is 11550 HS in California?

Health and Safety Code section 11550 prohibits using, or being under the influence of, listed controlled substances, which include methamphetamine, amphetamine, heroin, and cocaine, unless administered by or under the direction of a person licensed to dispense, prescribe, or administer them.

Is 11550 a misdemeanor?

Subdivision (a) says so expressly: a person convicted is guilty of a misdemeanor and shall be sentenced to not more than one year in county jail, and may be placed on probation for up to five years. The separate firearm offense in subdivision (e) is punishable by county jail up to one year or state prison.

What is the sentence for 11550(a)?

Not more than one year in county jail, possible probation of up to five years, and an optional fine of up to $70 under subdivision (d). The court may allow a licensed drug rehabilitation program in place of part or all of the jail time under subdivision (c).

What happens on a third 11550 conviction?

Under subdivision (b), if the offense occurred within seven years of two or more separate 11550(a) convictions and the person refuses a licensed drug rehabilitation program offered by the court, the punishment is county jail for 180 days to one year. The court cannot excuse the 180-day minimum unless no licensed program is reasonably available.

What is 11550(e)?

Subdivision (e) covers being unlawfully under the influence of cocaine, cocaine base, heroin, methamphetamine, or phencyclidine while in immediate personal possession of a loaded, operable firearm, which includes the passenger compartment of a vehicle. It is punishable by county jail up to one year or state prison, and a second or later conviction by state prison for two, three, or four years under subdivision (f).

Can a 11550 case go to drug court or deferred entry of judgment?

Subdivision (g) says section 11550 does not prevent deferred entry of judgment or a preguilty plea drug court program under Penal Code section 1000 and following, except that certain charges, including a subdivision (e) firearm charge, make a person ineligible. Eligibility itself is set by those Penal Code sections, which this page does not cover.