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The Healthcare Cost and Utilization Project (HCUP, pronounced "H-Cup") is a family of healthcare databases and related software tools and products developed through a Federal-State-Industry partnership and sponsored by the Agency for Healthcare Research and Quality (AHRQ). HCUP databases bring together the data collection efforts of State data organizations, hospital associations, private data organizations, and the Federal government to create a national information resource of encounter-level healthcare data (HCUP Partners). HCUP includes the largest collection of longitudinal hospital care data in the United States, with all-payer, encounter-level information beginning in 1988. These databases enable research on a broad range of health policy issues, including cost and quality of health services, medical practice patterns, access to healthcare programs, and outcomes of treatments at the national, State, and local market levels.

HCUP's objectives are to:
  • Create and enhance a powerful source of national, state, and all-payer healthcare data.
  • Produce a broad set of software tools and products to facilitate the use of HCUP and other administrative data.
  • Enrich a collaborative partnership with statewide data organizations aimed at increasing the quality and use of healthcare data.
  • Conduct and translate research to inform decision making and improve healthcare delivery.
HCUP Fact Sheet
For a quick reference guide, refer to the HCUP Fact Sheet (PDF file, 280 KB; HTML).
HCUP Databases
The HCUP Databases provide data beginning in 1988 and contain encounter-level information for all payers compiled in a uniform format with privacy protections in place.

HCUP databases include:

The National (Nationwide) Inpatient Sample (NIS) containing data on more than seven million hospital stays each year.

The Kids' Inpatient Database (KID) is a nationwide sample of pediatric inpatient discharges.

Nationwide Ambulatory Surgery Sample (NASS) is a set of ambulatory surgery databases.

The Nationwide Emergency Department Sample (NEDS) is a database that yields national estimates of emergency department (ED) visits.

The Nationwide Readmissions Database (NRD) is a unique and powerful database designed to support various types of analyses of national readmission rates.

The State Inpatient Databases (SID) contain the universe of inpatient discharge abstracts from participating states.

The State Ambulatory Surgery and Services Databases (SASD) include data for ambulatory surgery and other outpatient services from hospital-owned facilities.

The State Emergency Department Databases (SEDD) contain data from hospital-affiliated emergency departments for visits that do not result in hospitalizations.

Many of the HCUP databases are available for purchase through the HCUP Central Distributor.
  • NIS (starting with 1988)
  • KID (starting with 1997)
  • NASS (starting with 2016)
  • NEDS (starting with 2006)
  • NRD (starting with 2010)
  • SID (starting with 1995)
  • SASD (starting with 1997)
  • SEDD (starting with 1999)
HCUP Tools and Software
The HCUP databases have been a powerful resource for the development of tools, many of which can be applied to other similar databases by health services researchers and decision makers.

HCUPnet is a free, on-line query system based on data from the Healthcare Cost and Utilization Project (HCUP). It provides access to health statistics and information on hospital inpatient and emergency department utilization.

HCUP Fast Stats is an online query tool that uses visual displays to compare national or State statistics on a range of healthcare topics, such as trends by payer and opioid-related hospital and ED use.

The AHRQualityIndicators™ (QIs) are measures of healthcare quality that make use of readily available hospital inpatient administrative data. The AHRQ QIs consist of three modules measuring various aspects of quality. Software and user guides for all three modules are available to assist users in applying the Quality Indicators to their own data.

The Clinical Classifications Software (CCS), was developed with HCUP data and is available for downloading. The CCS provides a method for classifying diagnoses or procedures into clinically meaningful categories, which can be used for aggregate statistical reporting of a variety of types.

Additional HCUP tools can be found on the Tools & Software page.

Internet Citation: HCUP Overview. Healthcare Cost and Utilization Project (HCUP). February 2022. Agency for Healthcare Research and Quality, Rockville, MD.
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Last modified 2/10/22