When you download a Grouper package from the Download portal, you will receive a ZIP file containing the following files:

  ├── java-grouper-{VERSION}-all.jar
  ├── java-grouper-{VERSION}-javadoc.jar
  ├── java-grouper-{VERSION}.jar
  └── java-grouper-{VERSION}.pom
  • – A file describing the version history of the Grouper software
  • LICENSE-3RD-PARTY.txt – A file containing the open source software licenses of all third-party software that is packaged as part of this Grouper distribution. This file is available since version 1.2.0.
  • – A short readme file
  • java-grouper-{VERSION}-all.jar – An executable JAR containing all referenced Java classes that are necessary to run the grouper (including 3rd-party dependencies). Use this artifact if you want to use the grouper as an executable.
  • java-grouper-{VERSION}.jar – JAR without dependencies. Includes only the Java-Grouper classes. Use this artifact if you want to use the grouper as a library and if you want to resolve the dependencies yourself.
  • java-grouper-{VERSION}-javadoc.jar – Contains the Javadoc files for the Grouper software.
  • java-grouper-{VERSION}.pom – Maven POM file stating the 3rd-party dependencies that are required by the Grouper software.


Packages of 3rd-party dependencies in the executable JAR file are relocated in order to prevent version collisions with dependencies added by clients.


The JavaGrouper groups patients into DRGs according to the SwissDRG “Specifications”. These specifications represent a set of rules that define which patient is grouped into which DRG. The specifications are published three times a year in the Download Portal.

Each specification is a set of JSON files contained in one folder. The folder is named

<major version>.<minor version>   // for SwissDRG
t<major version>.<minor version>  // for TARPSY

where “major version” means either SwissDRG or TARPSY version (from 1 to currently 7 for the former); “minor version” is a integer between 0 and 3:

  • 0 = Catalog version
  • 1 = Planning version 1
  • 2 = Planning version 2
  • 3 = Billing version


  • 7.3 = SwissDRG V7.0, Billing version
  • t1.2 = TARPSY V1.0, planning version 2

In the Download Portal, there is a special Zip archive that contains all JSON specifications for SwissDRG versions V1.0 to V6.0.

The JSON specifications for the newer versions are also in the Download Portal under Spezifikationen: open the Zip archive of a given version and therein use the folder named e.g. 7.3 (meaning as described above).


The old C-Grouper used a binary format of the specifications (not JSON). These are also included in the Zip archives of SwissDRG versions 1 to 7 (but not anymore in later versions).


To calculate effective cost weights, the Java Grouper needs a catalog file: a list of DRGs (or “PCG”, in the case of TARPSY) that contains for each DRG their cost weights, among other information.

The catalogs are CSV files, included in the ZIP archive of the specifications.