The California Department of Health Care Access and Information (HCAI) provides confidential patient-level data sets to eligible hospitals and health departments. California Licensed Hospitals and Local Health Departments are eligible to request Limited Data Set versions of HCAI’s patient-level data. The 2004 law that allows for the release of these data was Assembly Bill 2876 (AB 2876), Health and Safety Code Section 128766. HCAI offers several types of non-public data to licensed California Hospitals and California Local Health Departments.  Eligible hospitals and local health departments may request Limited Model Data Sets for Patient Discharge Data, including Inpatient (PDD), Emergency Department (EDD), and Ambulatory Surgery Center (ASD).  They may also order Patient Origin/Market Share data (PO/MS), created to assist hospitals and communities facing tremendous budgetary pressures, which makes the need to understand key operating performance issues critical.  In addition, there are also Prevention Quality Indicators, a set of measures that can be used with hospital inpatient discharge data to identify quality of care for “ambulatory care sensitive conditions. This is data standardized for the Agency for Healthcare Research and Quality (AHRQ PQI.) 

2022 is the most recent year available for Patient Discharge, Emergency Department, and Ambulatory Surgery Data.

Limited Data Set

The Limited Data Set includes Inpatient (PDD), Emergency Department (EDD) and Ambulatory Surgery (AS) files. The contents of these files, including descriptions of the variables that they contain, are described in the non-public data documentation.  A cross-referenced list of variables across multiple years is contained in the Master Variable Grid.

Limited Data Set Request Forms

Use the information and forms below to confirm eligibility and help ensure needed information is included when requesting data. Below are the HCAI forms for requesting the limited data set, as well as the variable grids, separated by the requestor type. 

For additional information, see our Frequently Asked Questions.

California Licensed Hospitals Model Data Set Variable Grids

California Health Departments Model Data Set Variable Grids

Custom Data Set Justification Grids

Additional Data Products


Hospitals and communities face tremendous budgetary pressures, making the need to understand key operating performance issues critical.

The Patient Origin and Market Share (PO/MS) Report available to California licensed hospitals and Local Health Departments (AB2876-eligible requesters) includes facility, patient ZIP Code and county, age group, payer, and MS-DRG information. Data is available for 2008-2012; data can be requested for one or more years.  Visit the Open Data Portal for access to PO/MS reports for the general public. 

The PO/MS Reports support ZIP Code-based analyses, such as:

  • How big is the market?
  • Which hospital(s) control the market? (Top 5 by volume?)
  • What is the market share by service line?
  • Where do the residents of my county go for care?

AHRQ Quality Indicator

Two AHRQ Prevention Quality Indicator (PQI) products are available to California licensed hospitals and Local Health Departments.

These products provide indicators for preventable hospitalizations or ambulatory care-sensitive conditions, which can be used to assess healthcare quality and access. These indicators often reveal striking variations in healthcare for conditions that are potentially preventable through treatment in non-hospital settings and/or proper medication and management. The indicators are based on HCAI’s hospital patient discharge data and include conditions such as hypertension, diabetes, and asthma in the adult population. PQI reports for the general public are also available.

The PQI Summary Table and Record-Level File can be used for community health assessments, county and ZIP Code-level “hot-spotting,” and quality improvement monitoring and evaluation. These products can help answer questions about a community’s healthcare delivery system, such as:

  • What counties and ZIP Codes have the highest preventable hospitalization rates?
  • What are the most common preventable hospitalizations in California?
  • What is the distribution of preventable hospitalizations by age/race/ethnicity, gender, and payer?

For additional information, see our Frequently Asked Questions.

Frequently Asked Questions

How much does the data cost?

Data is provided complimentary to approved Limited Data requestors.

Who is eligible for limited data requests?

California Licensed Hospitals and Local Health Departments, as well as some State and Federal agencies, are eligible to receive the Limited Data Sets (formerly known as AB2876).  These are HIPAA limited data sets. Hospitals and Local Health Departments can also request Patient Origin/Market Share reports and AHRQ Prevention Quality Indicator Products within the request.  The “Limited Data Sets” were developed by HCAI to streamline the §128766 data request process for many hospitals and public health entities. The concept behind the limited data sets is that public health officials and hospitals could explain or justify in advance their need for certain data elements for certain common purposes so that each requester would not need to do so each time they requested non-public data under §128766. Before the first limited data sets were designed, there was a series of meetings with interested parties who explained their most common anticipated uses for the data and the data elements that were the minimum necessary for those uses. Each dataset contains a set of the least sensitive data elements that will meet the most common needs cited by these data requesters. The Limited Data Set Documentation provides the justification for the inclusion of each data element for datasets designed for certain purposes. When the data sets are requested for such purposes, the specific justification normally required for each individual data element can be waived.

If a hospital or public health entity wants to request a set of data elements different from those included in the “limited data sets” or a public file, they must justify the need for each data element individually, using the Justification Grids for a Custom Data Set, based on the same limited data files that the Limited Data Sets are developed from.

How long does it take to receive data after I submit a request?

Approximately 6-10 weeks from the beginning of review. Review time is dependent on corrections needed.

How is data shipped?

Data is sent via HCAI’s Secure File Transfer System. Find instructions here

What changes were made to the HCAI Limited Data Use Agreement?

Coinciding with the release of 2022 data (in fall 2023), language was added to help clarify the HCAI Limited Data Use Agreement allowing requesting entities to maintain no more than 10 years of HCAI data, unless specified in the application for data.  The language is designed to improve data safeguards around data management and retention and increase data security.

Why were changes made to HCAI’s Limited Data Use Agreement?

HCAI’s Data Use Agreement was updated in 2022 to improve data safeguards around data management and retention and increase data security.

Can an entity retain more than 10 years of data?

Local Health Departments and hospitals qualify to retain a maximum of 10 years of data. Entities that want to retain more than 10 years of data must submit the Supplemental Extension Form, which becomes part of the application. As specified in the Data Use Agreement, entities with an approved application may retain more than 10 years of data. 

Is Comma Label Format available?

Beginning with 2021 data, HCAI no longer offers Comma Label Format.

Can an entity request multiple file formats?

Only one file format is released per entity. HCAI recommends requesting .csv (comma-separated value) file format if entities are unsure about the format.

When is the data available?

Patient level data, i.e., PDD, ED, and AS data, is generally available annually by Early-August for eligible requestors.

What years of confidential data are available?

A Limited Data file is available for each year the inpatient discharge (PDD), emergency department (ED) or ambulatory surgery (AS) patient data was collected.

Can a private consultant or contractor order the Limited Data Sets?

No. However, a licensed California hospital or Local Health Department can request the data and submit a signed Business Associate Agreement with a contractor. The contractor would then be able to analyze the data for the hospital. All contacts for corrections and more information for Limited Data Set requests will be made through the contact listed on the request form, no information can be shared with the contractor or consultants.

Is there a template “Business Associate Agreement” available?

HCAI does not have a template Business Associate Agreement.

More information on Business Associate Agreements and their requirements as defined by HIPAA can be found here.

What purpose does the Data Use Agreement serve?

HIPAA specifically requires that the data use agreement must:

  • Establish the permitted uses and disclosures of the health information; these must be consistent with the stated purpose. The agreement may not authorize the recipient to use or further disclose the data in a manner that would violate the HIPAA regulations if done by the covered entity;
  • Establish who is permitted to use or receive the limited data set (including any agents and subcontractors)
  • Provide that the data recipient will:
  • Not use or further disclose the information other than as permitted by the agreement or as otherwise required by law.
  • Use appropriate safeguards to prevent use or disclosure of the information other than as provided for in the agreement (i.e., provide appropriate data security).
  • Report to the entity providing the information any use or disclosure that is not provided for in the agreement of which it becomes aware.
  • Ensure that any agents who have access to the information agree to the same restrictions and conditions that apply to the limited data set recipient with respect to such information.
  • Not identify the information or contact the individuals.

What is a “Limited Data Set”?

Under HIPAA, a Limited Data Set is a set of individually identifiable health information. The term “Limited Data Set” refers to a specific subset of data created for a specific purpose.

A Limited Data Set may be created and disclosed if a set of requirements are met:

  • The dataset does not contain any direct identifiers
    • Direct identifiers include name, address, Social Security Number, Medical Record Number, and many other items not included in HCAI’s data set.
    • Dates, ages, ZIP Codes, and Record Linkage Numbers (RLNs) are not considered “direct” identifiers.
  • The data will only be used for certain permitted purposes
    • Research the definition is the same as the definition used by CPHS (requests for research use must be reviewed by the CPHS)
    • Public health
    • Health care operations for hospitals, this includes business planning and development
  • The data set is created for a specific purpose, which must be clearly described
  • A detailed data use agreement must be in place
  • The dataset must contain only the minimum necessary information, the disclosure must be limited to the information reasonably necessary to accomplish the intended purpose. The request must explain how the data are necessary for the specific purpose.

HCAI’s Limited Data Sets are required to be consistent with the requirements of 45 CFR Section 164.514. The statutes that govern HCAI’s release of patient record-level data specify that only the minimum necessary data for the approved purpose may be released. In consultation with hospitals and local health officers HCAI has developed Limited Data Sets for inpatient discharge (PDD), emergency department (ED), and ambulatory surgery (AS) data. These data sets contain the data elements typically required for the functions of healthcare operations and public health activities; a standard justification for these data elements has been pre-approved. Additional data elements may be requested based on justification of need for these elements. Note that the direct identifiers collected in the HCAI data are not available for release under H&S Code 128766. The term “Limited Data Set” refers to a specific subset of data created for a specific purpose.