Assembly Bill 394: California’s Nurse-to-Patient Ratio Law

California’s nurse-to-patient ratio law is Assembly Bill 394, signed by Governor Gray Davis on October 10, 1999 and in force since January 1, 2004. It requires every general acute care hospital, acute psychiatric hospital, and special hospital in the state to maintain minimum, numerical licensed nurse-to-patient ratios that vary by unit, and it bars unlicensed staff from performing core nursing tasks.¹ California remains the only state with comprehensive mandatory ratios of this kind.

The Ratios by Hospital Unit

The Department of Health Services issued final ratio regulations on July 1, 2003, with compliance required beginning January 1, 2004. Several units had a stricter phase-in that took full effect on January 1, 2008.²

Intensive and critical care: 1:2
Neonatal intensive care: 1:2
Operating room: 1:1
Postanesthesia recovery: 1:2
Labor and delivery: 1:2
Emergency room, general patients: 1:4
Emergency room, ICU-level patients: 1:2
Emergency room, trauma patients: 1:1
Pediatrics: 1:4
Psychiatric: 1:6
Medical-surgical: 1:5 (was 1:6 before 2008)
Telemetry: 1:4 (was 1:5 before 2008)
Step-down: 1:3 (was 1:4 before 2008)

These numbers are floors, not ceilings. Hospitals must also keep the patient classification systems required under Title 22 of the California Code of Regulations, which assess staffing needs shift by shift. If the classification system calls for more nurses than the minimum ratio, the hospital is expected to staff to the higher figure.³

The ratios must be maintained at all times, including holidays, weekends, and staff leaves of absence. Ongoing patterns of understaffing do not qualify as “unpredictable circumstances,” the exemption hospitals had previously used to explain gaps.⁴

What the Law Requires Beyond the Numbers

AB 394 places significant restrictions on the use of unlicensed assistive personnel. Hospitals cannot assign unlicensed workers to perform nursing functions in place of a registered nurse. The barred tasks include medication administration, intravenous therapy, tube feedings, invasive procedures such as catheter insertion and tracheal suctioning, patient assessment, patient and family education, and moderately complex laboratory tests.¹

Hospitals must adopt written policies for orienting and training direct patient care staff. A nurse cannot be assigned to a unit without first receiving orientation and demonstrating competence. Temporary and agency personnel are held to the same standard.¹

The statute defines “hospital unit” broadly, covering critical care, burn, labor and delivery, postanesthesia, emergency, operating room, pediatric, step-down and intermediate care, specialty care, telemetry, general medical, subacute, and transitional inpatient units. Rural hospitals, University of California teaching hospitals, and Los Angeles County hospitals received specific accommodations, with the LA County facilities given a phase-in period.¹

How the Ratios Are Enforced

The California Department of Public Health enforces the law through periodic, unannounced inspections. A first violation carries an administrative fine of $15,000; a second, $30,000.⁴

Governor Gavin Newsom signed Senate Bill 596 on October 13, 2025, sharpening enforcement in two ways. Each day a violation continues is now treated as a separate offense, so penalties can stack quickly. And a new tier applies when a violation poses “immediate jeopardy” to patients: up to $75,000 for a first offense, $100,000 for a second, and $125,000 for later violations.⁵

SB 596 also tightened the rules around on-call lists. Hospitals must keep those lists current and verifiable, and calling nurses who are not actually scheduled to be on-call does not count as a good-faith compliance effort.⁴

Where the Law Applies

The ratios apply to California general acute care hospitals, acute psychiatric hospitals, and special hospitals. They do not extend to nursing homes, outpatient clinics, physician offices, or hospitals outside California. There is no federal law setting nurse-to-patient ratios in U.S. hospitals; a bicameral bill, the Nurse Staffing Standards for Hospital Patient Safety and Quality Care Act, was introduced on May 12, 2025 by Representative Jan Schakowsky and Senators Alex Padilla and Jeff Merkley, but it is not law.⁶

Acute psychiatric hospitals were formally brought under mandatory ratios by California Department of Public Health emergency regulations that took effect June 1, 2026. Those rules set a minimum of one licensed nurse per six adult patients and one per five pediatric patients at all times, closing what regulators described as a gap that had allowed psychiatric facilities to run leaner than general hospitals.⁷ The rollout has been contested. The California Nurses Association objected to counting licensed vocational nurses and psychiatric technicians in the ratio, arguing only registered nurses should. The California Hospital Association and the California Behavioral Health Association warned that the timeline could force psychiatric bed closures given behavioral health workforce shortages. In the first week of implementation, Kern, Contra Costa, Madera, and San Diego counties reported bed closures averaging a 15 percent loss of acute psychiatric beds per county, with statewide compliance costs estimated at $145.2 million.⁵ A permanent rulemaking process is scheduled.

How the Law Came to Be

AB 394 was authored by Assemblymember Sheila Kuehl and sponsored by the California Nurses Association, which had been pushing for mandated ratios for years. A 1996 ballot measure that would have addressed staffing standards, Proposition 216, did not pass.⁸ A 1998 bill from Kuehl, AB 695, passed the legislature but was vetoed by Governor Pete Wilson, who said existing rules were sufficient and that mandates would “tie the hands of hospitals.”⁹

After Gray Davis succeeded Wilson, the CNA ran a large campaign for AB 394. The bill was amended during negotiations to hand DHS authority to set the final numbers after study, and Davis signed only after supporters agreed to extend the DHS deadline by at least a year. In his signing statement, Davis said “staffing in many hospitals has fallen below an acceptable level” and had “result[ed] in an erosion in the quality of patient care.”¹⁰

Hospital groups had opposed the bill. The California Healthcare Association, the California Association of Catholic Hospitals, and individual hospitals argued that numerical ratios were “unrealistic, unnecessary and unlikely to result in improved patient care,” pointing to a severe nursing shortage — California ranked last among the 50 states in registered nurses per 100,000 population at the time — and to the existing Title 22 classification system as a more flexible tool.¹¹

What Research Says About Its Effects

More than two decades in, the evidence on whether the law improved patient outcomes is mixed. On staffing itself, the picture is clear: it went up. One study estimated a 21 percent increase in the nurse-to-patient ratio in acute care units, or roughly 58 additional minutes of nursing time per patient per day at hospitals that had to adjust. Hospitals often met the new requirements by hiring younger, less-experienced registered nurses and expanding the use of licensed vocational nurses, agency staff, and per diem workers. The same analysis found treated hospitals cut an average of 16 beds, about a 14 percent reduction, while raising utilization on the beds that remained.¹²

On patient safety, findings diverge. A 2010 study led by Dr. Linda Aiken of the University of Pennsylvania found that California nurses cared for an average of one fewer patient than their counterparts in New Jersey and Pennsylvania and estimated that matching California’s ratios would have cut surgical deaths by 13.9 percent in New Jersey and 10.6 percent in Pennsylvania.¹³ A study of 410 California hospitals by the University of California, San Francisco found “no evident change” in patient length of stay or adverse safety events attributable to the ratios; measures including pressure ulcers, failure to rescue, deep vein thrombosis, and postoperative sepsis showed no direct change linked to the increased staffing.¹⁴ A 2010 National Bureau of Economic Research working paper likewise found “no evidence of a causal impact of the law on patient safety.”¹⁵

Emergency departments saw some operational strain. Studies reported longer ED wait times, patient boarding in hallways, and diversions tied to the ratios, as strict staffing floors sometimes prevented hospitals from admitting patients when a nurse was not available.¹⁶

On the cost side, hospitals subject to the mandate faced a 9 percent increase in their total wage bill, though researchers described the actual cost effects as “far smaller than estimated in prior descriptive work.” The UCSF study concluded that broader factors, including shifts in Medicare and Medi-Cal payment rates and seismic building requirements, exerted far greater financial pressure on hospitals than the ratios themselves.¹⁴

1
California Legislative Information. AB 394 Chapter 945 Chaptered Text
2
Connecticut General Assembly. California RN Staffing Ratios
3
California Health Care Foundation. Minimum Nurse Staffing Ratios in California Acute Care Hospitals
4
Healthcare Finance News. California Warns Hospitals of Tougher Enforcement for Violating Nurse Staffing Ratios
5
Holland & Knight. California Enacts Mandatory Nurse-to-Patient Staffing Ratios for Acute Psychiatric Hospitals
6
Schakowsky.house.gov. Schakowsky, Padilla, Merkley Introduce Bicameral Bill to Strengthen Nursing Staff
7
CalMatters. Emergency Psychiatric Staffing Rules Delayed
8
California Secretary of State. Proposition 216 Argument in Favor
9
Los Angeles Times. Wilson Vetoes Nurse Staffing Ratio Bill
10
CaliforniaHealthline. Nurse Staffing: Davis Signs Bill Mandating Ratios
11
California Legislative Information. AB 394 Senate Committee Analysis, Health and Human Services
12
ScienceDirect. Impact of California Nurse Staffing Mandate
13
The Commonwealth Fund. Researchers Say California Nurse Staffing Law Has Reduced Patient Mortality
14
California Health Care Foundation. Assessing California’s Nurse Staffing Ratios
15
National Bureau of Economic Research. The Effect of Hospital Nurse Staffing on Patient Health Outcomes, Working Paper 16077
16
IHA. Nurse Staffing Ratios Studies Compilation