MS-DRG

Column	Data Type	Description

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Maintenance Instructions

CMS releases a list of MS-DRG codes twice a year effective April 1 and October 1. This list only contains valid codes and omits any that have been deprecated. Tuva maintains these deprecated code so historical data can be analyzed.

1. Navigate to the CMS MS DRG website
2. Under the section "MS-DRG Definitions Manual and Software", click on "V42 Definitions Manual Table of Contents - Full Titles - HTML Version"
   • The version (e.g. V42) will change with each new release.
3. Click on the hyperlink "Appendix A List of MS-DRGs Version 42.1"
4. Click on the hyperlink "List of MS-DRGs Version 42.1"
5. Copy and paste the list of MS-DRGs into any text editor and save it as a text file.
6. Format the file
   • Remove the text "MDC" from column 2
   • Wrap the description in column 4 with double quotes so commas are interpreted correctly

Note: you can use the below script to format the file as said in number 6.

import pandas as pd

def main():
    input_filename = "your text file path"
    output_filename = "output csv file path"  
    
    with open(input_filename, 'r') as f:
        lines = f.readlines()

    rows = []
    for line in lines:
        line = line.strip() 
        if line:  # ignore empty lines
            parts = line.split(",", 3)  # split only at the first 3 commas
            rows.append(parts)
    
    df = pd.DataFrame(rows, columns=["Code", "Group", "Type", "Description"])

    print(df.head())

    # Clean the Group column (remove 'MDC ' if exists)
    df["Group"] = df["Group"].str.replace("MDC ", "", regex=False).str.strip()

    df.to_csv(output_filename, index=False, header=True)

if __name__ == "__main__":
    main()

7. Save the file
8. Import the csv file into any data warehouse that also has the previous version of MS-DRG loaded
9. Use the SQL below to populate the deprecated and deprecated_date columns. The script does the following:
   1. Compares the old file with the new file to determine if codes have been deprecated. If they have been, set the column "deprecated" to 1 and "deprecated_date" to the date the newest codes were published (i.e. the beginning of the current fiscal year)
   2. UNIONs the list of deprecated codes with new valid codes
   3. Cleans up any formatting issues with the output and creates a table.

-- create table from the output of the script
create table [ms_drg_new] as

-- compare the old codes with the new codes and only return codes that are missing
with depreacted_ms_drg_codes as(
  select
      old.ms_drg_code
      , old.mdc_code
      , old.medical_surgical
      , old.ms_drg_description
      , 1 as deprecated
      , case when deprecated = 0 then '2023-10-01'
          else deprecated_date
    end as deprecated_date
  from [previous_ms_drg_codes] old
  left join [current_ms_drg_codes] new
      on old.ms_drg_code = new.ms_drg_code
  where new.ms_drg_code is null
)

-- union valid codes and depreacted codes together
, union_all_codes as(
select 
  ms_drg_code
  , mdc_code
  , medical_surgical
  , 0 as deprecated
  , null as deprecated_date 
from [current_ms_drg_codes]
where ms_drg_code not in (select ms_drg_code from depreacted_ms_drg_codes)

union all

select
   ms_drg_code
  , mdc_code
  , medical_surgical
  , deprecated
  , deprecated_date
from depreacted_ms_drg_codes
  
)

-- clean up formatting as necessary
select
    trim(ms_drg_code) as ms_drg_code
    , nullif(trim(mdc_code),'') as mdc_code
    , trim(medical_surgical) as medical_surgical
    , trim(ms_drg_description) as ms_drg_description
    , trim(deprecated) as deprecated
    , trim(deprecated_date) as deprecated_date
from union_all_codes

10. Upload the newly created code list into S3 (credentials with write permissions to the S3 bucket are required)

-- example code for Snowflake
copy into s3://tuva-public-resources/terminology/ms_drg.csv
from [table_created_in_step_9]
file_format = (type = csv field_optionally_enclosed_by = '"')
storage_integration = [integration_with_s3_write_permissions]
OVERWRITE = TRUE;

11. Create a branch in docs. Update the last_updated column with the current date (above).
12. Submit a pull request

The below steps are only required if the headers of the file need to be changed. The Tuva Project does not store the contents of the ms-drg file in GitHub.

1. Create a branch in The Tuva Project
2. Alter the headers as needed in MS-DRG file
3. Submit a pull request