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NASS Summary Statistics

The following links provide summary statistics for the Nationwide Ambulatory Surgery Sample (NASS). Summary Statistics include means on all numeric variables, frequency distributions, and univariates on continuous variables. Summary statistics are provided by year.

Contents:

2023 NASS
2022 NASS
2021 NASS
2020 NASS
2019 NASS
2018 NASS
2017 NASS
2016 NASS

2023 NASS

SumStats NASS 2023 Encounter File, unweighted (PDF file, 181 KB)
SumStats NASS 2023 Encounter File, weighted (PDF file, 185 KB)
SumStats NASS 2023 Hospital File (PDF file, 123 KB)
SumStats NASS 2023 Supplemental File (PDF file, 157 KB)
SumStats NASS 2023 Diagnosis and Procedure Groups File, unweighted (PDF file, 184 KB)
SumStats NASS 2023 Diagnosis and Procedure Groups File, weighted (PDF file, 185 KB)

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2022 NASS

SumStats NASS 2022 Encounter File, unweighted (PDF file, 186 KB)
SumStats NASS 2022 Encounter File, weighted (PDF file, 189 KB)
SumStats NASS 2022 Hospital File (PDF file, 126 KB)
SumStats NASS 2022 Supplemental File (PDF file, 157 KB)
SumStats NASS 2022 Diagnosis and Procedure Groups File, unweighted (PDF file, 179 KB)
SumStats NASS 2022 Diagnosis and Procedure Groups File, weighted (PDF file, 180 KB)

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2021 NASS

SumStats NASS 2021 Encounter File, unweighted (PDF file, 240 KB)
SumStats NASS 2021 Encounter File, weighted (PDF file, 241 KB)
SumStats NASS 2021 Hospital File (PDF file, 128 KB)
SumStats NASS 2021 Supplemental File (PDF file, 104 KB)
SumStats NASS 2021 Diagnosis and Procedure Groups File, unweighted (PDF file, 184 KB)
SumStats NASS 2021 Diagnosis and Procedure Groups File, weighted (PDF file, 186 KB)

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2020 NASS

Encounter File, unweighted (PDF file, 233 KB)
Encounter File, weighted (PDF file, 234 KB)
Hospital File (PDF file, 129 KB)
Supplemental File (PDF file, 104 KB)
Diagnosis and Procedure Groups File, unweighted (PDF file, 182 KB)
Diagnosis and Procedure Groups File, weighted (PDF file, 185 KB)

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2019 NASS

Encounter File, unweighted (PDF file, 223 KB)
Encounter File, weighted (PDF file, 224 KB)
Hospital File (PDF file, 131 KB)
Supplemental File (PDF file, 165 KB)
Diagnosis and Procedure Groups File, unweighted (PDF file, 182 KB)
Diagnosis and Procedure Groups File, weighted (PDF file, 185 KB)

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2018 NASS

Encounter File, unweighted (PDF file, 207 KB)
Encounter File, weighted (PDF file, 208 KB)
Hospital File (PDF file, 113 KB)
Supplemental File (PDF file, 162 KB)
Diagnosis and Procedure Groups File, unweighted (PDF file, 179 KB)
Diagnosis and Procedure Groups File, weighted (PDF file, 181 KB)

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2017 NASS

Encounter File, unweighted (PDF file, 261 KB)
Encounter File, weighted (PDF file, 262 KB)
Hospital File (PDF file, 120 KB)
Supplemental File (PDF file, 200 KB)

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2016 NASS

Encounter File, unweighted (PDF file, 261 KB)
Encounter File, weighted (PDF file, 262 KB)
Hospital File (PDF file, 120 KB)
Supplemental File (PDF file, 200 KB)

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Internet Citation: NASS Summary Statistics. Healthcare Cost and Utilization Project (HCUP). January 2026. Agency for Healthcare Research and Quality, Rockville, MD. hcup-us.ahrq.gov/db/nation/nass/nasssummstats.jsp.

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Last modified 01/14/26