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Central Distributor SASD: Description of Data Elements

HCUP_AS - HCUP indicator of ambulatory surgery record
Documentation Sections:
General Notes
Uniform Values
State Specific Notes
General Notes

HCUP_AS indicates records that have evidence of ambulatory surgery (AS) services reported on the HCUP record. A value of 1 or more indicates that there is evidence of AS services. A value of 0 marks records that do not include evidence of AS services. It is possible that records with HCUP_AS=0 did in fact have AS services, but that information was not captured on the HCUP record.

Evidence of AS services includes:

  • Ambulatory surgery ICD-9-CM procedure code on record. The ICD-9-CM AS procedure range includes codes 00.50-86.99 (excluded are procedure codes in the range 88.4-88.59 that were part of the 2003 screen for identifying records to be included in the SASD).
  • Center for Medicare and Medicaid Services (CMS) approved ambulatory surgery center CPT-4/HCPCS procedure code on record. Yearly updates are downloaded from CMS at In general, the list includes CPT-4/HCPCS codes: 10121-69930, G0105, G0121, and G0260.
  • Presence of at least one revenue center code in the following range: 036x (operating room services), 037x (anesthesia), 049x (ambulatory surgical care).
  • Presence of a UB92 bill type of 83x indicating outpatient services.
Uniform Values
VariableDescriptionValueValue Description
HCUP_ASHCUP indicator of ambulatory surgery record0Record does not meet any HCUP Ambulatory Surgery criteria
1Ambulatory Surgery ICD-9-CM procedure code on record
2Ambulatory Surgery CPT procedure code on record
3Ambulatory Surgery revenue code on record
4UB-92 bill type of "83X"
State Specific Notes


Beginning in 2007, Maryland included the records for encounter type 05 from all other outpatients, Greenbaum cancer center, and UMMS shock trauma in the unified AS and ED outpatient data file. Previously, Maryland only included outpatient records with encounter types 01-04 in the file provided to HCUP. The inclusion of these new records resulted in a large increase in the frequency of HCUP_AS = 0 or HCUP_AS = 1.


Internet Citation: HCUP Central Distributor SASD Description of Data Elements - All States. Healthcare Cost and Utilization Project (HCUP). May 2024. Agency for Healthcare Research and Quality, Rockville, MD.
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Last modified 5/22/24