Key findings
In 2024, an estimated 82.15% of California adults who needed substance use treatment didn't get it — roughly 4 in 5, or about 4.76 million people (95% range: 78.47%–85.32%, or 4.31–5.26 million). Young adults ages 18–25 had the highest estimate, 88.10% (84.00%–91.26%), but most people going without were older: about 3.77 million adults 26 and up, or 79.0% of the total (ARC calculation). California's gap was about the same as the nation's (81.18%; 79.84%–82.45%). Source: SAMHSA's 2023–2024 National Surveys on Drug Use and Health (NSDUH) state estimates, 2024 data.
In a crisis, call or text 988 (Suicide & Crisis Lifeline). In an emergency, call 911. If you think someone is overdosing, call 911.
Looking for adult addiction treatment for yourself or someone you care about? Call Addiction Resource Center (ARC) at 530-625-7910.
Last updated: November 13, 2026 (America/Los_Angeles).
Data current as of: SAMHSA 2023–2024 NSDUH State Estimates (published December 17, 2025), 2024 data; accessed November 13, 2026.
Written by Addiction Resource Center. Reviewed by Tiffany Komba, LMFT (California LMFT #136055).
These figures are public survey estimates. They are not ARC treatment outcomes.
How many Californians needed addiction treatment but didn't get it?
About 4.76 million California adults needed substance use treatment in 2024 and didn't receive any (range 4.31–5.26 million). That's 82.15% of the roughly 5.82 million adults who needed it (range 5.29–6.40 million).
Flip it around and fewer than 1 in 5 got care: about 17.85% (range 14.68%–21.53%; ARC calculation, 100% minus SAMHSA's figure).
License: Charts and derived CSV by Addiction Resource Center (sayarc.com), CC BY 4.0. Source data: Substance Abuse and Mental Health Services Administration (SAMHSA), National Survey on Drug Use and Health (NSDUH). Underlying SAMHSA data belong to SAMHSA, not ARC.
Who is most likely to go without treatment?
Young adults had the highest share: an estimated 88.10% of Californians ages 18–25 who needed treatment didn't get it (84.00%–91.26%) — nearly 9 in 10. For adults 26 and older, it was 80.69% (76.21%–84.50%). The two ranges overlap a little, so treat the age difference as a likely pattern, not an exact gap.
But in raw numbers, the gap is mostly a grown-up problem. About 3.77 million of the people going without were 26 or older (range 3.35–4.23 million), compared with about 998,000 ages 18–25 (range 867,000–1,143,000). That makes adults 26+ about 79.0% of California's untreated adults (ARC calculation).
License: Charts and derived CSV by Addiction Resource Center (sayarc.com), CC BY 4.0. Source data: Substance Abuse and Mental Health Services Administration (SAMHSA), National Survey on Drug Use and Health (NSDUH). Underlying SAMHSA data belong to SAMHSA, not ARC.
How does California compare with the rest of the U.S.?
About the same. Nationally, 81.18% of adults who needed substance use treatment in 2024 didn't get it (79.84%–82.45%), versus 82.15% in California (78.47%–85.32%). Because those ranges overlap, the survey can't say California is better or worse.
California is big, though: its estimated 4.76 million untreated adults are about 11.7% of the nation's estimated 40.73 million (ARC calculation).
What counts as "needing treatment"?
- Needing treatment: In the past year, the person met the clinical criteria (DSM-5) for an alcohol or drug use disorder, or they got substance use treatment.
- Got treatment: Any substance use treatment in the past year — inpatient, outpatient, telehealth, medication for alcohol or opioid use disorder, or treatment in a jail or prison.
- Didn't get treatment: Needed it, by the definition above, but reported none.
This definition doesn't depend on whether someone wanted treatment, so the gap includes people who didn't seek it as well as people who couldn't get it.
California and U.S. estimates, 2024
Download the table: California and U.S. adult substance use treatment need and receipt, 2024, NSDUH (CSV) (california_adult_addiction_treatment_gap_2024.csv).
License: Charts and derived CSV by Addiction Resource Center (sayarc.com), CC BY 4.0. Source data: Substance Abuse and Mental Health Services Administration (SAMHSA), National Survey on Drug Use and Health (NSDUH). Underlying SAMHSA data belong to SAMHSA, not ARC.
| Place and age group | Needed treatment, % of age group | Needed treatment, thousands | Did not receive, % of those who needed it | Did not receive, thousands | Received treatment, % of age group | Received treatment, thousands |
|---|---|---|---|---|---|---|
| California, All adults (18+) | 19.05% (17.30–20.94) | 5,824 (5,289–6,400) | 82.15% (78.47–85.32) | 4,763 (4,305–5,260) | 3.35% (2.68–4.17) | 1,024 (820–1,275) |
| California, Ages 18–25 | 27.53% (23.83–31.58) | 1,121 (970–1,285) | 88.10% (84.00–91.26) | 998 (867–1,143) | 3.29% (2.44–4.44) | 134 (99–181) |
| California, Ages 26+ | 17.75% (15.89–19.77) | 4,703 (4,211–5,240) | 80.69% (76.21–84.50) | 3,765 (3,345–4,227) | 3.36% (2.61–4.31) | 890 (692–1,141) |
| United States, All adults (18+) | 19.13% (18.51–19.76) | 50,172 (48,559–51,828) | 81.18% (79.84–82.45) | 40,731 (39,315–42,188) | 3.60% (3.33–3.89) | 9,442 (8,726–10,214) |
| United States, Ages 18–25 | 26.75% (25.69–27.84) | 9,349 (8,977–9,730) | 88.67% (87.17–90.02) | 8,290 (7,932–8,658) | 3.03% (2.66–3.45) | 1,059 (928–1,207) |
| United States, Ages 26+ | 17.96% (17.28–18.65) | 40,824 (39,289–42,405) | 79.47% (77.89–80.96) | 32,441 (31,105–33,824) | 3.69% (3.38–4.02) | 8,383 (7,695–9,130) |
What does this mean for families and referring clinicians?
These are statewide survey numbers, so they can't tell you about any one person or program. What they do show is that needing treatment and getting it are often far apart. If you're a family member, a therapist, or a primary care clinician trying to connect an adult with care, a clear next step and a named contact can help.
- Families: how to help a family member with addiction.
- Therapists and medical providers: refer a patient to ARC.
- Adults who need care that fits around work: ARC's intensive outpatient program (IOP) and telehealth IOP.
Frequently asked questions
Google may not show FAQ rich results for health content; these answers are written so people and answer engines can quote a short, sourced reply.
How many California adults who needed addiction treatment didn't get it in 2024?
An estimated 82.15% of California adults who needed substance use treatment in 2024 did not receive it (95% range 78.47%–85.32%), or about 4.76 million people, according to SAMHSA's 2023-2024 National Surveys on Drug Use and Health state estimates.
Is California's addiction treatment gap worse than the national average?
Not measurably. In 2024, 82.15% of California adults who needed substance use treatment did not receive it, compared with 81.18% of U.S. adults. The 95% ranges (78.47%–85.32% and 79.84%–82.45%) overlap, so SAMHSA's estimates do not show a clear difference.
What does "needing substance use treatment" mean in this survey?
SAMHSA counts an adult as needing substance use treatment if, in the past year, they met DSM-5 criteria for an alcohol or drug use disorder or they received substance use treatment. The definition does not depend on whether a person wanted treatment.
Technical notes
These details sit here so the takeaways above stay easy to read. Every figure is unchanged from SAMHSA's tables unless labeled as an ARC calculation or a display rounding.
Citation: Substance Abuse and Mental Health Services Administration (SAMHSA), Center for Behavioral Health Statistics and Quality. 2023-2024 National Surveys on Drug Use and Health: Model-Based Prevalence Estimates and Estimated Totals (50 States and the District of Columbia), Tables 30-32 (2024 data). Published December 17, 2025. Accessed November 13, 2026. https://www.samhsa.gov/data/data-we-collect/nsduh-national-survey-drug-use-and-health/state-releases/2023-2024
- Source tables: Table 31 (classified as needing substance use treatment in the past year), Table 32 (did not receive substance use treatment in the past year among people classified as needing treatment), and Table 30 (received substance use treatment in the past year), from SAMHSA's 2023–2024 NSDUH Model-Based Prevalence Estimates (percent tables) and Model-Based Estimated Totals (totals in thousands). Files downloaded as CSV on November 13, 2026.
- 2024 only: Although the release is labeled 2023–2024, SAMHSA's methodology guide says state estimates for all substance use treatment measures use only 2024 data, because questionnaire changes made 2024 treatment estimates not comparable with 2022 and 2023. Don't compare these numbers with earlier NSDUH treatment-gap figures.
- Ranges: State estimates are model-based (survey-weighted hierarchical Bayes small area estimation). Each range is a 95% Bayesian credible interval as published by SAMHSA. The "Total U.S." row uses design-based estimates and 95% confidence intervals. Ranges are not symmetric around the estimate.
- Possible undercount of the gap: SAMHSA notes that many respondents who reported inpatient or outpatient treatment did not name a substance ("substance unspecified"). If some of them did not actually receive substance use treatment, overall treatment estimates could be overestimates — which would make the true gap larger than shown. SAMHSA's guide: https://www.samhsa.gov/data/sites/default/files/reports/rpt56959/2024-nsduh-sae-guide-state-meth/2024-nsduh-sae-guide-state-meth.htm.
- Definition of need: Respondents were classified as needing substance use treatment if they had a substance use disorder (DSM-5 criteria for alcohol or drug use disorder) in the past year or received substance use treatment in the past year. Receipt includes inpatient, outpatient, telehealth, medications for alcohol or opioid use disorder, and treatment in a prison, jail, or juvenile detention center.
- Display rounding: SAMHSA reports numbers in thousands (for example, 4,763 thousand). The page shows them in millions to two decimals (4.76 million) or as whole numbers (998,000 for 998 thousand). "4 in 5" summarizes 82.15%; "nearly 9 in 10" summarizes 88.10%; "fewer than 1 in 5" summarizes 17.85%. The waffle chart rounds 82.15% to 82 of 100 squares.
- ARC calculations (not published by SAMHSA, no published range): 17.85% received treatment = 100% − 82.15% (range 14.68%–21.53% = 100% minus each end of SAMHSA's range). Adults 26+ as a share of untreated California adults = 3,765 ÷ 4,763 thousand = 79.0% (the 18–25 and 26+ totals, 998 + 3,765, add to the 18+ total of 4,763). California's share of U.S. untreated adults = 4,763 ÷ 40,731 thousand = 11.7%.
- Why "received" isn't "needed minus didn't receive": Each measure is modeled separately, so subtracting one SAMHSA total from another won't exactly match the published "received" figure. This page uses SAMHSA's published Table 30 numbers (1.02 million California adults received treatment; 3.35% of all adults, range 2.68%–4.17%).
- Comparisons: California and U.S. ranges overlap for all adults, ages 18–25, and ages 26+, so the page does not rank California against the U.S. or other states. California's 18–25 and 26+ ranges overlap slightly (84.00%–91.26% vs. 76.21%–84.50%).
- Geography: State-level estimates only. NSDUH does not publish county estimates; the latest substate-region estimates cover 2021–2023 and are not used here. There are no Yuba County or Sutter County treatment-gap figures in this source.
- Survey scope: NSDUH covers the civilian, noninstitutionalized population; it does not include people experiencing homelessness who are not in shelters, active-duty military, or people living in institutions such as jails and hospitals. Age groups here are adults 18+ only.
- This table is modified: The HTML table and CSV are ARC's reformatting of SAMHSA's published tables. They are not an official government data table.
- License: ARC-derived charts and CSVs on this page are licensed CC BY 4.0. That license covers ARC's charts, HTML table layout, and derived CSV only. Underlying source data belong to SAMHSA and are cited here via the release page (isBasedOn). ARC did not find a license statement on the SAMHSA release page when checked on November 13, 2026.
- Refresh cadence: SAMHSA publishes NSDUH state estimates once a year (the 2023–2024 release was published December 17, 2025). Recheck the NSDUH state releases page quarterly, and update this page when the 2024–2025 state estimates are posted.
These numbers are not ARC treatment outcomes.
If you need help
ARC provides comprehensive adult addiction treatment through its intensive outpatient program (IOP) in Yuba City, with telehealth available. Call 530-625-7910 or see admissions. Clinicians can refer a patient. For statewide service context, see behavioral health services in California.
In a crisis, call or text 988. In an emergency or a suspected overdose, call 911. More ARC data explainers: California overdose data, including California fentanyl deaths by county, 2024 and California overdose deaths vs. ED visits.
Embed this chart
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<img src="https://sayarc.com/images/dataviz/california-adult-addiction-treatment-gap-2024-waffle.webp" width="1200" height="1020" alt="Waffle chart: 82.15% of California adults who needed substance use treatment in 2024 did not receive it. Source: SAMHSA NSDUH, via Addiction Resource Center.">
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Chart and CSV by <a href="https://sayarc.com/learning-center/california-addiction-treatment-gap/">Addiction Resource Center</a> (sayarc.com), <a href="https://creativecommons.org/licenses/by/4.0/">CC BY 4.0</a>.
Source data: Substance Abuse and Mental Health Services Administration (SAMHSA), National Survey on Drug Use and Health (NSDUH). Underlying SAMHSA data belong to SAMHSA, not ARC.
Data citation: SAMHSA, 2023-2024 NSDUH State Estimates, Tables 30-32 (2024 data), accessed November 13, 2026.
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Please keep the link back to this page so readers can see the ranges, table, and methods. The chart is a static image, so this embed uses an image and a backlink rather than an iframe.