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MS-DRG Classifications and Software

Notice regarding upcoming releases of the ms-drg grouper and mce.

The current versions of the MS-DRG Grouper and MCE use Java software and are currently based on Java version 8.   Support for Java version 8 will end by November 2026.     Hospitals and their software vendors who implement these programs in a mainframe environment will be impacted by this change. CMS is preparing now to convert the programs to Java version 17.   

For the upcoming year, the Fiscal Year 2025 releases of these programs, effective October 2024, will include two Common Business-Oriented Language (COBOL) Java bridge modules instead of the one that is currently delivered.  CMS will continue to provide the existing bridge module that utilizes the 31-bit, Java 8 Java Virtual Machine (JVM) environment.   We will also provide a new bridge module that will utilize the 64-bit, Java 17 JVM.  The Java jar file for each will continue to be compiled using Java 8.  This will preserve backwards compatibility with all existing mainframe deployments (both batch and Customer Information Control System (CICS)).  The installation guides for the programs will provide notice of the changes.  This will allow users to test upgrades to their systems over the next year to prepare to move to Java 17. 

The release of the Fiscal Year 2026 release of these programs, effective October 2025, will be compiled with Java 17 and only the Java 17, 64-bit COBOL calling module will be delivered.  Providers and their software vendors should begin planning this year to ensure they are prepared for this conversion next fall.  

Questions about the Java 17 conversion can be sent at any time to the resource mailbox [email protected] .  

Section 1886(d) of the Act specifies that the Secretary shall establish a classification system (referred to as DRGs) for inpatient discharges and adjust payments under the IPPS based on appropriate weighting factors assigned to each DRG.  Therefore, under the IPPS, we pay for inpatient hospital services on a rate per discharge basis that varies according to the DRG to which a beneficiary's stay is assigned. The formula used to calculate payment for a specific case multiplies an individual hospital's payment rate per case by the weight of the DRG to which the case is assigned.  Each DRG weight represents the average resources required to care for cases in that particular DRG, relative to the average resources used to treat cases in all DRGs.

Congress recognized that it would be necessary to recalculate the DRG relative weights periodically to account for changes in resource consumption.  Accordingly, section 1886(d)(4)(C) of the Act requires that the Secretary adjust the DRG classifications and relative weights at least annually.  These adjustments are made to reflect changes in treatment patterns, technology, and any other factors that may change the relative use of hospital resources.

Currently, cases are classified into Medicare Severity Diagnosis Related Groups (MS-DRGs) for payment under the IPPS based on the following information reported by the hospital: the principal diagnosis, up to 24 additional diagnoses, and up to 25 procedures performed during the stay.  In a small number of MS-DRGs, classification is also based on the age, sex, and discharge status of the patient.  Effective October 1, 2015, the diagnosis and procedure information is reported by the hospital using codes from the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) and the International Classification of Diseases, Tenth Revision, Procedure Coding System (ICD-10-PCS).

For additional information on the MS-DRG system, including yearly reviews and changes to the MS-DRGs, please view prior Inpatient Prospective Payment System (IPPS) proposed and final rules located in the left navigational area of this page.

Any MS-DRG related inquiries should be sent to the  [email protected] mailbox. 

PROCESS FOR REQUESTING ANNUAL MS-DRG CLASSIFICATION CHANGES

Effective April 5, 2022, the new electronic intake system, Medicare Electronic Application Request Information System TM (MEARIS TM ), became available as an initial release for users to begin gaining familiarity with a new approach and process to submit MS-DRG classification change requests. MEARIS TM , including the mechanism for submitting MS-DRG classification change requests, can be accessed at: https://mearis.cms.gov .

Accordingly, beginning with the FY 2024 MS-DRG classification change requests, CMS will now only accept such requests submitted via MEARIS TM . Request for annual MS-DRG classification changes submitted through the [email protected] mailbox will no longer be considered.

Latest News

ICD-10 MS-DRGs V41.1 Effective April 1, 2024 (PDF)

ICD-10 MS-DRGs V40.1 Effective April 1, 2023 (ZIP)  - Updated 11/25/2022

ICD-10 MS-DRGs V39.1 Effective April 1, 2022  (ZIP)  - Updated 11/16/2021

ICD-10 MS-DRGs V38.1 Effective January 1, 2021 (ZIP)

ICD-10 MS-DRGs Version 37.2 Effective August 01, 2020 (PDF)

July 2020 Quarterly Update to the Inpatient Prospective Payment System (IPPS) Fiscal Year (FY) 2020 Pricer (PDF)

ICD-10 MS-DRGs Version 37.1 R1 Effective April 1, 2020 - Updated March 23, 2020 (PDF)

ICD-10 MS-DRGs Version 37.1 Effective April 1, 2020 (PDF)  

MS-DRG CC/MCC Comprehensive Analysis Information

CMS hosted a listening session that described the Medicare-Severity Diagnosis-Related Group (MS‑DRG) Complication and Comorbidity (CC)/Major Complication and Comorbidity (MCC) Comprehensive Analysis discussed in the FY 2020 Inpatient Prospective Payment System (IPPS) proposed and final rules. This listening session included a review of the methodology to measure the impact on resource use and provided an opportunity for CMS to receive public input on this analysis and to address any clarifying questions in order to assist the public in formulating written comments on the current severity level designations for consideration in future rulemaking.

This listening session was held on October 8, 2019; 2:00 – 3:00 PM ET.

For the transcript and audio file of the listening session, visit https://www.cms.gov/Outreach-and-Education/Outreach/OpenDoorForums/Downloads/10082019ListingSessionTrasncriptandQandAsandAudioFile.zip .

Link to the supplementary file that was made available for the listening session:

• ICD-10-CM Diagnosis Codes Impact on Resource Use File - FY 2018 MedPAR (ZIP)    

We are providing updated impact on resource use files so that the public can review the mathematical data for the impact on resource use generated using claims from the FY 2019 - FY 2023 MedPAR files:

• ICD-10-CM Diagnosis Codes Impact on Resource Use File - FY2019 and FY2020 MedPAR (ZIP)
• ICD-10-CM Diagnosis Codes Impact on Resource Use File - FY2021 MedPAR (ZIP)
• ICD-10-CM Diagnosis Codes Impact on Resource Use File - FY2022 MedPAR (ZIP)
• ICD-10-CM Diagnosis Codes Impact on Resource Use File - FY2023 MedPAR (ZIP)

MS-DRG Definitions Manual and Software

Fy 2025 – version 42 (effective october 1, 2024 through march 31, 2025).

• Definition of Medicare Code Edits Version 42 (ZIP) : The ICD-10 Definition of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2025. Zip file contains a PDF and text file that is 508 compliant.
• ICD-10 MS-DRG Definitions Manual Files V42 (ZIP) Updated – 08/06/2024 : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) which contains the complete documentation of the ICD-10 MS-DRG Grouper logic.
• V42 Definitions Manual Table of Contents - Full Titles - HTML Version coming soon. 
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V42  MAINFRAME Software (ZIP)
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V42, ICD-10 PC Software (ZIP)
• Medicare Severity Diagnosis Related Group (MS-DRG) and Medicare Code Editor (MCE) Version 42 Java Source Code and Reference Implementation Binaries (ZIP)

FY 2025 – Version 42 Test GROUPER – DRAFT file for FY 2025 IPPS/LTCH PPS Proposed Rule

This is a supporting file for the FY 2025 IPPS/LTCH PPS Proposed Rule .

We are providing a test version of the ICD-10 MS-DRG GROUPER Software, Version 42, so that the public can better analyze and understand the impact of the proposals included in the FY 2025 IPPS/LTCH PPS proposed rule. This test software reflects the proposed GROUPER logic for FY 2025.  For additional information regarding the Version 42 Test GROUPER please see the file titled CMS-1808-P Table 6P.1a-6P.1b below.

In addition, users are able to view the draft version of the Definition of Medicare Code Edits Version 42 and the ICD-10 MS-DRG Definitions Manual, Version 42.  

• Draft Definition of Medicare Code Edits Version 42 (ZIP) : The draft ICD-10 Definition of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2025. Zip file contains a PDF and text file that is 508 compliant.
• Proposed ICD-10 MS-DRG Definitions Manual Files V42 (ZIP) : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the proposed ICD-10 MS-DRG Grouper logic.
• Proposed ICD-10-CM/PCS MS-DRG V42 Definitions Manual Table of Contents - Full Titles - HTML Version
• Medicare Severity Diagnosis Related Group (MS-DRG) Test Grouper Software and Medicare Code Editor (MCE) Version 42, ICD-10 PC Software (ZIP)
• CMS-1808-P Table 6P.1a-6P.1b (ZIP) : An Excel file that contains the mapped Version 42 FY 2025 ICD-10-CM codes and the deleted Version 41 FY 2024 ICD-10-CM codes and the mapped Version 42 FY 2025 ICD-10-PCS codes and the deleted Version V41.1 FY 2024 ICD-10-PCS codes that should be used for testing purposes with users’ available claims data.

FY 2024 – Version 41.1 (Effective April 1, 2024 through September 30, 2024)

• Definition of Medicare Code Edits V41.1 (ZIP)  The ICD-10 Definitions of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2024. Zip file contains a PDF and text file that is 508 compliant.
• ICD-10 MS-DRG Definitions Manual Files V41.1 (ZIP)  A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the ICD-10 MS-DRG Grouper logic. - Updated 03/12/2024
• V41.1 Definitions Manual Table of Contents - Full Titles - HTML Versions - Updated 03/12/2024
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V41.1  MAINFRAME Software (ZIP) - Updated 03/12/2024
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V41.1, ICD-10 PC Software (ZIP) - Updated 03/12/2024
• Medicare Severity Diagnosis Related Group (MS-DRG) and Medicare Code Editor (MCE) Version 41.1 Java Source Code and Reference Implementation Binaries (ZIP) - Updated 03/14/2024
• Version 41.1 Appendix C Suppression Logic (PDF) - Updated 03/12/2024  

FY 2024 – Version 41.A Alternate Test GROUPER – DRAFT file for FY 2024 IPPS/LTCH PPS Proposed Rule

This is a supporting file for the FY 2024 IPPS/LTCH PPS Proposed Rule .

We are providing an alternate test version of the ICD-10 MS-DRG GROUPER Software, Version 41.A, so that the public can better analyze and understand the impact of the proposals with application of the NonCC Subgroup Criteria included in the FY 2024 IPPS/LTCH PPS proposed rule. This alternate test software reflects the proposed GROUPER logic for FY 2024 with application of the NonCC Subgroup Criteria.  For additional information regarding the Version 41.A Alternate Test GROUPER please see the file titled CMS-1785-P Table 6P.1a below.

• Medicare Severity Diagnosis Related Group (MS-DRG) Alternate Test Grouper Software and Medicare Code Editor (MCE) Version 41.A, ICD-10 PC Software (ZIP)
• CMS-1785-P Table 6P.1a (ZIP) :  An Excel file that contains the mapped Version 41 FY 2024 ICD-10-CM codes and the deleted Version 40.1 FY 2023 ICD-10-CM codes that should be used for testing purposes with users’ available claims data.
• Definition of Medicare Code Edits V41 (ZIP) : The ICD-10 Definitions of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2024. Zip file contains a PDF and text file that is 508 compliant.
• ICD-10 MS-DRG Definitions Manual Files V41 (ZIP) : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the ICD-10 MS-DRG Grouper logic. - Updated 10/16/2023
• V41 Definitions Manual Table of Contents - Full Titles - HTML Versions   - Updated 10/23/2023
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V41  MAINFRAME Software (ZIP)  
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V41, ICD-10 PC Software (ZIP)  
• Medicare Severity Diagnosis Related Group (MS-DRG) and Medicare Code Editor (MCE) Version 41 Java Source Code and Reference Implementation Binaries (ZIP) - Updated 8/22/2023

Java Source Code vs. Executable Jars

• The Java Source Code (JAR files) are provided for transparency around the grouping and editing methodology internals. These files are not intended for direct use in applications but offer an opportunity for users to have some additional insight into the component’s inner workings.
• In addition to the source files, precompiled jar files and instructions are provided which can be used on any platform running Java.

We are providing a test version of the ICD-10 MS-DRG GROUPER Software, Version 41, so that the public can better analyze and understand the impact of the proposals included in the FY 2024 IPPS/LTCH PPS proposed rule. This test software reflects the proposed GROUPER logic for FY 2024.  For additional information regarding the Version 41 Test GROUPER please see the file titled CMS- 1785-P Table 6P.1a below.

In addition, users are able to view the draft version of the ICD-10 MS-DRG Definitions Manual, Version 41. 

• Proposed ICD-10 MS-DRG Definitions Manual Files V41 (ZIP) : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the proposed ICD-10 MS-DRG Grouper logic. 
• Proposed ICD-10-CM/PCS MS-DRG V41 Definitions Manual Table of Contents - Full Titles - HTML Version
• Medicare Severity Diagnosis Related Group (MS-DRG) Test Grouper Software and Medicare Code Editor (MCE) Version 41, ICD-10 PC Software (ZIP)
• CMS-1785-P Table 6P.1a (ZIP) :  An Excel file that contains the mapped Version 41 FY 2024 ICD-10-CM codes and the deleted Version 40.1 FY 2023 ICD-10-CM codes that should be used for testing purposes with users’ available claims data
• Definition of Medicare Code Edits V40.1 (ZIP)  The ICD-10 Definitions of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2023. Zip file contains a PDF and text file that is 508 compliant.
• ICD-10 MS-DRG Definitions Manual Files V40.1 (ZIP) A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the ICD-10 MS-DRG Grouper logic.
• V40.1  Definitions Manual Table of Contents - Full Titles - HTML Versions
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V40.1  MAINFRAME Software (ZIP)
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V40.1, ICD-10 PC Software (ZIP)
• Medicare Severity Diagnosis Related Group (MS-DRG) and Medicare Code Editor (MCE) Version 40.1 Java Source Code and Reference Implementation Binaries (ZIP)

09/02/2022 Update: We are providing a re-release of the version 40 software to reflect updates that have been made to enhance the performance of the software. These updates do not affect any testing or grouping results.

For both the MS-DRG and MCE Java Mainframe software packages the following changes were made to the executable software.

• The class hierarchy of common class files was name spaced to remove any potential conflict when multiple grouping or editing Java applications are run by a single larger program on the Mainframe
• The Logging Error Message referring to “slf4j.impl.StaticLoggerBinder” has been corrected so this warning no longer appears. (This warning had no effect on the component functionality).
• Please refer to the Sample Environment file in the java folder to add “COBJVMINITOPTIONS=-Djzos.merge.sysout=true” to the Environment file on your USS system. For MS-DRG, refer to folder CMSDRG400_MF_Java_jar. For MCE, refer to folder MCEV400_MF_Java_jar folder.
• The COBOL wrapping programs provided have been enhanced to add “redirectStandardStreams” which allows greater flexibility in the location of log files on the Mainframe system

For the MS-DRG Mainframe reference files the following changes and clarifications are provided.

• For the DXPATERN file, The ‘XXX’ entries were removed from the file; these were placeholders for empty attributes (codes with no attributes for the OPERAND column) and were inadvertently left in.
• For the PRPATERN file, the ‘nonor’ attribute was not in the legacy flat files, but now appears. It is a better representation of the operating room severity levels - the ‘nonor’ attribute is meant to indicate the procedures that are non-operating room procedures. The PRATTLST file was annotated to include this attribute. 
• FORMULA_COLLECTION_ID column removed from the file, it is an internal field that is unnecessary for users.
• There is an attribute in the formulas, called ‘ORPROC’ that appears in many of the DRG formulas. This does not appear in the PRATTLST anywhere. This is meant to indicate codes that are operating room procedures, either extensive (attribute d68) or non-extensive (attribute d477). Replaced all mention of ‘ORPROC’ with ‘d468 OR d477’ in the DRGLOGIC file (both attributes already appear in the PRATTLST file). 
• Definition of Medicare Code Edits V40 (ZIP) : The ICD-10 Definitions of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2023. Zip file contains a PDF and text file that is 508 compliant.
• ICD-10 MS-DRG Definitions Manual Files V40 (ZIP) : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the ICD-10 MS-DRG Grouper logic. 
• V40 Definitions Manual Table of Contents - Full Titles - HTML Versions  
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V40  MAINFRAME Software (ZIP)  - Updated 11/03/2022: This is a replacement of the previously released Medicare Severity Diagnosis Related Groups v40.0 I-10 z/OS (Java) Batch Mainframe Software.  The updated zip file addresses the POA logic flag that was not recognizing the POA Exempt status X in the Mainframe wrapper. 
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V40, ICD-10 PC Software (ZIP)
• Medicare Severity Diagnosis Related Group (MS-DRG) and Medicare Code Editor (MCE) Version 40 Java Source Code and Reference Implementation Binaries (ZIP)

This is a supporting file for the FY 2023 IPPS/LTCH PPS Proposed Rule

We are providing a test version of the ICD-10 MS-DRG GROUPER Software, Version 40, so that the public can better analyze and understand the impact of the proposals included in the FY 2023 IPPS/LTCH PPS proposed rule. This test software reflects the proposed GROUPER logic for FY 2023.  For additional information regarding the Version 40 Test GROUPER please see the file titled CMS-1771-P Table 6P.1a below.

In addition, users are able to view the draft version of the ICD-10 MS-DRG Definitions Manual, Version 40.

• Proposed ICD-10 MS-DRG Definitions Manual Files V40 (ZIP) : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the proposed ICD-10 MS-DRG Grouper logic.
• Proposed ICD-10-CM/PCS MS-DRG V40 Definitions Manual Table of Contents - Full Titles - HTML Version
• Medicare Severity Diagnosis Related Group (MS-DRG) Test Grouper Software and Medicare Code Editor (MCE) Version 40, ICD-10 PC Software (ZIP)
• CMS-1771-P Table 6P.1a (ZIP) : An Excel file that contains the mapped Version 40 FY 2023 ICD-10-CM codes and the deleted Version 39.1 FY 2022 ICD-10-CM codes that should be used for testing purposes with users’ available claims data.

Update 07/18/2022 : We are providing a re-release of the version 39.1 software to reflect the standalone Java MCE binaries, sources, and documentation zip file in the PC software.  These updates do not affect any testing or grouping results

• Definition of Medicare Code Edits V39.1 (ZIP)   - Updated 3/14/22: The ICD-10 Definitions of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2022. Zip file contains a PDF and text file that is 508 compliant.
• ICD-10 MS-DRG Definitions Manual Files V39.1 (ZIP)   - Updated 3/18/22: A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the ICD-10 MS-DRG Grouper logic.
• V39.1  Definitions Manual Table of Contents - Full Titles - HTML Versions  - Updated 3/18/22
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V39.1  MAINFRAME Software (ZIP)  -   Updated 3/14/22
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V39.1, ICD-10 PC Software (ZIP)  -   Updated 7/18/22

Update 12/22/2021 : The Apache Log4j open-source logging software library is used in the PC and Java based grouping and editing software (MS-DRG Java, MCE Java, MSGMCE). Recently, a vulnerability was discovered in Log4j that could present security issues when running under certain conditions. The Mainframe BAL software is not impacted.

Apache has issued an updated version of Log4j (2.16.0) to fix this issue. The updated software removes any potential association with the vulnerability.

There is no impact or change to any grouping or editing results or data files.

We have provided updated software files in order to remove any potential association with the vulnerability.

MS-DRG and MCE Mainframe Java distribution updates:

• Removed Log4j from the MS-DRG Mainframe and MCE Mainframe Java software packages as this logging is not utilized in this environment
• Updated the documentation for the standalone Java MS-DRG and MCE to reference 2.16.0 of Log4j

MSGMCE Products

•  Updated the Log4j version used to 2.16.0 from the current versions (MSGMCE PC - 2.7)
•   Definition of Medicare Code Edits V39 (ZIP)   :The ICD-10 Definitions of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2022. Zip file contains a PDF and text file that is 508 compliant.   
• ICD-10 MS-DRG Definitions Manual Files V39 (ZIP) : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the ICD-10 MS-DRG Grouper logic.   
• V39  Definitions Manual Table of Contents - Full Titles - HTML Versions  
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version 39  MAINFRAME Software (ZIP)   - Updated 12/22/21  
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version 39, ICD-10 PC Software (ZIP)  - Updated 12/22/21

This is a supporting file for the FY 2022 IPPS/LTCH PPS Proposed Rule

We are providing a test version of the ICD-10 MS-DRG GROUPER Software, Version 39, so that the public can better analyze and understand the impact of the proposals included in the FY 2022 IPPS/LTCH PPS proposed rule. This test software reflects the proposed GROUPER logic for FY 2022. For additional information regarding the Version 39 Test GROUPER please see the file titled CMS-1752-P Tables 6P.1a and 6P.1b below.

In addition, users are able to view the draft version of the ICD-10 MS-DRG Definitions Manual, Version 39.

• Proposed ICD-10 MS-DRG Definitions Manual Files V39 (ZIP) : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the proposed ICD-10 MS-DRG Grouper logic.
• Proposed ICD-10-CM/PCS MS-DRG V39 Definitions Manual Table of Contents - Full Titles - HTML Version
• Medicare Severity Diagnosis Related Group (MS-DRG) Test Grouper Software and Medicare Code Editor (MCE) Version 39, ICD-10 PC Software (ZIP)
• CMS-1752-P Table 6P.1a and 6P.1b (ZIP) : An Excel file that contains the mapped Version 39 FY 2022 ICD-10-CM and ICD-10-PCS codes and the deleted Version 38 FY 2021 ICD-10-CM and ICD-10-PCS codes that should be used for testing purposes with users’ available claims data.
• Definition of Medicare Code Edits V38.1 (ZIP) : The ICD-10 Definitions of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2021. Zip file contains a PDF and text file that is 508 compliant.
• ICD-10 MS-DRG Definitions Manual Files V38.1 (ZIP) : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the ICD-10 MS-DRG Grouper logic. 
• V38.1  Definitions Manual Table of Contents - Full Titles - HTML Versions
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V38.1  MAINFRAME Software (ZIP)
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V38.1, ICD-10 PC Software (ZIP)

The MS-DRG Java zip file has been updated to include a missing dependency required for testing. The MS-DRG Java API and calling example documentation has been updated to include references to this dependency as well as corrections to make method naming consist. The MS-DRG and MCE Java Mainframe deliverables have updated install guide PDF with corrections for clarity. There were no changes made to the functionality or content of MS-DRG or MCE.

Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Java Beta Version 38.1 MAINFRAME Software (ZIP)   - UPDATED 5.24.21

Inquiries related to this Java Beta version of the Grouper should be directed to  [email protected]

Errata (PDF) : A document describing the changes from Version 38 to Version 38.0 R1

• Definition of Medicare Code Edits V38.0 R1 (ZIP) :  The ICD-10 Definitions of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2021. Zip file contains a PDF and text file that is 508 compliant
• ICD-10 MS-DRG Definitions Manual Files V38.0 R1 (ZIP) :  A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the ICD-10 MS-DRG Grouper logic. 
• V38.0 R1 Definitions Manual Table of Contents - Full Titles - HTML Versions 
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V38.0 R1 MAINFRAME Software (ZIP)
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version V38.0 R1, ICD-10 PC Software (ZIP)

This is a supporting file for the FY 2021 IPPS/LTCH PPS Proposed Rule  

We are providing a test version of the ICD-10 MS-DRG GROUPER Software, Version 38, so that the public can better analyze and understand the impact of the proposals included in the FY 2021 IPPS/LTCH PPS proposed rule. This test software reflects the proposed GROUPER logic for FY 2021.  For additional information regarding the Version 38 Test GROUPER please see the file titled CMS-1735-P Table 6P.1a below.

In addition, users are able to view the draft version of the ICD-10 MS-DRG Definitions Manual, Version 38. 

• Proposed ICD-10 MS-DRG Definitions Manual Files V38 (ZIP) : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the proposed ICD-10 MS-DRG Grouper logic. 
• Proposed ICD-10-CM/PCS MS-DRG V38 Definitions Manual Table of Contents - Full Titles - HTML Version
• Medicare Severity Diagnosis Related Group (MS-DRG) Test Grouper Software and Medicare Code Editor (MCE) Version 38, ICD-10 PC Software (ZIP)
• CMS-1735-P Table 6P.1a (ZIP) : An Excel file that contains the mapped Version 38 FY 2021 ICD-10-CM codes and the deleted Version 37 FY 2020 ICD-10-CM codes that should be used for testing purposes with users’ available claims data.
• Definition of Medicare Code Edits V37.2 (ZIP) :The ICD-10 Definitions of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2020. Zip file contains a PDF and text file that is 508 compliant.
• ICD-10 MS-DRG Definitions Manual Files V37.2 (ZIP) : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the ICD-10 MS-DRG Grouper logic. 
• V37.2 Definitions Manual Table of Contents - Full Titles - HTML Versions
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version 37.2   MAINFRAME Software (ZIP)      
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version 37.2, ICD-10 PC Software (ZIP)  
• Definition of Medicare Code Edits V37.1 R1 (ZIP) : The ICD-10 Definitions of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2020. Zip file contains a PDF and text file that is 508 compliant
• ICD-10 MS-DRG Definitions Manual Files V37.1 R1 (ZIP)   : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the ICD-10 MS-DRG Grouper logic.  
• ICD-10-CM/PCS MS-DRG V37.1 R1 Definitions Manual Table of Contents - Full Titles - HTML Versions - UPDATED
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version 37.1 R1   MAINFRAME Software (ZIP)  
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version 37.1 R1, ICD-10 PC Software (ZIP)   (ZIP)
• Definition of Medicare Code Edits v37 (ZIP) : The ICD-10 Definitions of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2020. Zip file contains a PDF and text file that is 508 compliant.
• ICD-10 MS-DRG Definitions Manual Files v37 R1 (Updated September 19, 2019) (ZIP) : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the ICD-10 MS-DRG Grouper logic.
• ICD-10-CM/PCS MS-DRG v37 R1 Definitions Manual Table of Contents - Full Titles - HTML Versions-UPDATED - Opens in a new window    
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper MAINFRAME Software and ERRATA, v37 R1 (Updated September 18, 2019) (ZIP)    
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version 37, ICD-10 PC Software - Opens in a new window
• Definition of Medicare Code Edits v36 (ZIP) : The ICD-10 Definitions of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2019. Zip file contains a PDF and text file that is 508 compliant.
• Errata and ICD-10 MS-DRG Definitions Manual Files v36 R1 (Updated October 09, 2018) (ZIP) : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the ICD-10 MS-DRG Grouper logic. 
• ICD-10-CM/PCS MS-DRG v36 R1 Definitions Manual Table of Contents - Full Titles - HTML Versions (Updated October 12, 2018)
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version 36, ICD-10 Software - Opens in a new window    
• Definition of Medicare Code Edits v35 (ZIP) : The ICD-10 Definitions of Medicare Code Edits file contains the following: A description of each coding edit with the corresponding code lists as well as all the edits and the code lists effective for FY 2018. Zip file contains a PDF and text file that is 508 compliant.
• ICD-10 MS-DRG Definitions Manual Files v35 (Updated September 12, 2017) (ZIP) : A zip file with the ICD-10 MS DRG Definitions Manual (Text Version) contains the complete documentation of the ICD-10 MS-DRG Grouper logic.
• ICD-10-CM/PCS MS-DRG v35 Definitions Manual Table of Contents - Full Titles - HTML Versions (Updated September 13, 2017)
• Medicare Severity Diagnosis Related Group (MS-DRG) Grouper Software and Medicare Code Editor (MCE) Version 35 R1, ICD-10 Software (ZIP, 125MB) - Opens in a new window    

HCPCS-MS-DRG Definitions Manual and Software

The 21 st Century Cures Act requires that by January 1, 2018, the Secretary develop an informational “HCPCS version” of at least 10 surgical MS-DRGs.  Under the HCPCS version of the MS-DRGs developed for this requirement, to the extent feasible, the MS-DRG assignment for a given service furnished to an outpatient (billed using a HCPCS code) is as similar as possible to the MS-DRG assignment for that service if furnished to an inpatient (billed using an ICD-10-PCS code).

The HCPCS-MS-DRG definitions manual and software developed under the requirements of section 15001 of the 21st Century Cures Act (Public Law 114–255). Questions about the posted HCPCS-MS-DRG definitions manual and software can be directed to [email protected] .

• HCPCS-DRG V1.0 Software, User Manual, Definitions Manual, and Test Case Files - Opens in a new window    

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Hospital Patient Financial Services

Description of coding and drg assignment.

nsforming the verbal description of disease, injuries and procedures into numerical codes. Every patient encounter will be assigned these numerical codes based on the review of the provider’s documentation. Therefore all diagnostic or procedural statements should be accurate , specific, complete and descriptive of the patient’s condition. Accurate documentation results in accurate coding which is essential to reflect the severity of illness, complexity of care provided and consumption of resources.

These codes are utilized and reported both internally and externally. Codes and the data generated from coding are used internally for reimbursement, strategic and fiscal planning, clinical research, assessment of quality, physician profiling and other clinical and administrative purposes.

These same codes and data generated from coding are reported externally to various public and private agencies, such as Medicare/ Medicaid, Texas Medical Foundation, Census Bureau, State and Local Health Departments as well as many national ranking or benchmarking institutions including but not limited to Leap Frog Group, University Healthsystem Consortium, Hospital Compare, Healthgrades and others.

All codes are assigned by highly skilled and trained individuals nationally certified to perform Coding. Code assignment is dictated by the Rules and Guidelines established and updated annually by the Federal Government. Not adhering to these guidelines for documentation and coding constitutes fraud and is subject to prosecution.

A few of these guidelines/definitions that are important for you to be familiar with are listed below:

All Diagnosis that affect the current patient encounter must documented and coded. This requirement includes conditions that coexist at the time of admission or develop subsequently and affect the treatment received and/or the length of stay. Diagnoses that relate to an earlier admission, but which have no bearing on the current admission are to be excluded from coding. Diagnosis that are suspected and are treated empirically or cannot be ruled-out are to be included as diagnostic statements in the patient’s record and coded accordingly. Signs, symptoms and observations should be documented as a diagnosis whenever possible to provide adequate substantiation of coding for severity of illness and risk of mortality.

All diagnostic statements should be accurate , specific, complete and descriptive of the patient’s condition.

Significant Procedure : A significant procedure is one that carries an operative or anesthetic risk or requires highly trained personnel or special equipment. All significant procedures are to be documented in the patient record. (see Procedure&Operative Notes)

Codes are sequenced into Diagnoses Related Groups (or DRGs) to determine reimbursement from third party payers. DRGs are determined by the principal procedure, or the principal diagnosis if no procedure exists, and the presence of other conditions.

DRGs group patients with similar resource consumption, severity of illness and length of stay into payment groups.

DRGs are used for determining reimbursement and as an indicator for other types of reporting such as budgeting, physician profiling, clinical outcomes, case mix calculation and clinical research.

Description of Outpatient Hospital Coding

Coding is transforming the verbal description of disease, injuries and procedures into numerical codes. Every patient encounter will be assigned these numerical codes based on the review of the provider’s documentation. Therefore all diagnostic or procedural statements should be accurate , specific, complete and descriptive of the patient’s condition. Accurate documentation results in accurate coding which is essential to reflect the severity of illness, complexity of care provided and consumption of resources

All codes are assigned by highly skilled and trained individuals nationally certified to perform Coding. Code assignment is dictated by the Rules and Guidelines established and updated annually by the Federal Government. Not adhering to these guidelines for documentation and coding constitutes fraud and is subject to criminal prosecution.

• Hospital Outpatient coders code the following services:
• Day Surgery that are not admitted to inpatient
• Observation encounters not changed to a full admit
• Labor&Delivery Triage
• PT/OT services
• Outpatient Lab that requires a diagnostic code for reimbursement
• Health Care
• UTMB Support Areas