MS-DRG Conversion Update
Janice Bonazelli, 3M
Rhonda Butler, 3M
ICD-9-CM Coordination and
 Maintenance Committee 
March 11, 2009

ICD-10 MS-DRG Conversion 
• MS-DRGs conversion process 
• MS-DRG ICD-10 conversion report
– Conversion of all medical DRGs is complete
– Conversion of surgical DRGs is underway
– Appendices still to be converted
– Final ICD-10 version of MS-DRGs will be subject to rulemaking
• ICD-10 MS-DRG definitions manual format options

Condensed ICD-10 Descriptions
For this presentation—
Examples may contain condensed codes and descriptions
• All ICD-10 Codes—An asterisk (*) means all valid possibilities for codes in that category or subcategory are included
– A00* Cholera (3 codes)
• All three ICD-10-CM cholera codes apply to the example
• ICD-10-PCS Codes—All valid possibilities for an axis of classification are displayed in square brackets
– 0DN9[034]ZZ Release Duodenum (3 codes)
• All three ICD-10-PCS approaches apply to the example

MS-DRG Conversion Goals
• Coded in I-9 or I-10, the same patient is assigned to the same MS-DRG 
• Clinically equivalent
• Definitions manual has familiar look and feel

MDC 6, DISEASES & DISORDERS OF THE DIGESTIVE SYSTEM

A00* Cholera (3 codes)
A020 Salmonella enteritis
A03* Shigellosis (6 codes)
A04* Other bacterial intestinal infections (10 codes)
A050 Foodborne staphylococcal intoxication
A052 Foodborne Clostridium perfringens [Clostridium welchii] intoxication
A053 Foodborne Vibrio parahaemolyticus intoxication
A054 Foodborne Bacillus cereus intoxication
A055 Foodborne Vibrio vulnificus intoxication
A058 Other specified bacterial foodborne intoxications
A059 Bacterial foodborne intoxication, unspecified

MS-DRG Conversion Requirements
• Uses only I-10 codes 
• Replicates current DRG logic
– Minor departures where necessary
DRG 335 Peritoneal adhesiolysis w MCC
DRG 336 Peritoneal adhesiolysis w CC
DRG 337 Peritoneal adhesiolysis w/o CC/MCC

Operating Room Procedures
0DN8[0234]ZZ Release Small Intestine (4 codes)
0DN9[0234]ZZ Release Duodenum (4 codes)
0DNA[0234]ZZ Release Jejunum (4 codes)
0DNB[0234]ZZ Release Ileum (4 codes)
0DNC[034]ZZ Release Ileocecal Valve (3 codes)
0DN[EFG][0234]ZZ Release Large Intestine (12 codes)
0DNH[0234]ZZ Release Cecum (4 codes)
0DNJ[0234]ZZ Release Appendix (4 codes)
0DNK[0234]ZZ Release Ascending Colon (4 codes)
0DNL[0234]ZZ Release Transverse Colon (4 codes)
0DNM[0234]ZZ Release Descending Colon (4 codes)
0DNN[0234]ZZ Release Sigmoid Colon (4 codes)
0DN[ST]*** Release Omentum (6 codes)
0DNV*** Release Mesentery (3 codes)
0DNW*** Release Peritoneum (3 codes)
MS-DRG Conversion Principle
	Wherever possible, assign an I-10 code to the same DRG(s) as the I-9 code it was translated to in the I-10 to I-9 GEM

Find and Replace
Diagnosis Codes
DRG385 INFLAMMATORY BOWEL DISEASE W MCC
DRG386 INFLAMMATORY BOWEL DISEASE W CC
DRG387 INFLAMMATORY BOWEL DISEASE W/O CC/MCC
PRINCIPAL DIAGNOSIS
5550 Reg enteritis, sm intest
5551 Reg enteritis, lg intest
5552 Reg enterit sm/lg intest
5559 Regional enteritis NOS
DRG 385 Inflammatory bowel disease w MCC
DRG 386 Inflammatory bowel disease w CC
DRG 387 Inflammatory bowel disease w/o CC/MCC

Principal Diagnosis
K5000 Crohn's disease of small intestine without complications
K50011 Crohn's disease of small intestine with rectal bleeding
K50012 Crohn's disease of small intestine with intestinal obstruction
K50013 Crohn's disease of small intestine with fistula
K50014 Crohn's disease of small intestine with abscess
K50018 Crohn's disease of small intestine with other complication
K50019 Crohn's disease of small intestine with unspecified complications
K5010 Crohn's disease of large intestine without complications
K50111 Crohn's disease of large intestine with rectal bleeding
K50112 Crohn's disease of large intestine with intestinal obstruction
K50113 Crohn's disease of large intestine with fistula
K50114 Crohn's disease of large intestine with abscess
K50118 Crohn's disease of large intestine with other complication
K50119 Crohn's disease of large intestine with unspecified complications
K5080 Crohn's disease of both small and large intestine without complications
K50811 Crohn's disease of both small and large intestine with rectal bleeding
K50812 Crohn's disease of both small and large intestine with intestinal obstruction
K50813 Crohn's disease of both small and large intestine with fistula
K50814 Crohn's disease of both small and large intestine with abscess
K50818 Crohn's disease of both small and large intestine with other complication

Find and Replace
Procedure Codes
DRG335 PERITONEAL ADHESIOLYSIS W MCC
DRG336 PERITONEAL ADHESIOLYSIS W CC
DRG337 PERITONEAL ADHESIOLYSIS W/O CC/MCC
OPERATING ROOM PROCEDURES
5451 Lap periton adhesiolysis
5459 Oth periton adhesiolysis
DRG 335 Peritoneal adhesiolysis w MCC
DRG 336 Peritoneal adhesiolysis w CC
DRG 337 Peritoneal adhesiolysis w/o CC/MCC
Operating Room Procedures: lysis
0DN80ZZ Release Small Intestine, Open Approach
0DN82ZZ Release Small Intestine, Open Endoscopic Approach
0DN83ZZ Release Small Intestine, Percutaneous Approach
0DN84ZZ Release Small Intestine, Percutaneous Endoscopic Approach
0DN90ZZ Release Duodenum, Open Approach
0DN92ZZ Release Duodenum, Open Endoscopic Approach
0DN93ZZ Release Duodenum, Percutaneous Approach
0DN94ZZ Release Duodenum, Percutaneous Endoscopic Approach
0DNA0ZZ Release Jejunum, Open Approach
0DNA2ZZ Release Jejunum, Open Endoscopic Approach
0DNA3ZZ Release Jejunum, Percutaneous Approach
0DNA4ZZ Release Jejunum, Percutaneous Endoscopic Approach
0DNB0ZZ Release Ileum, Open Approach
0DNB2ZZ Release Ileum, Open Endoscopic Approach
0DNB3ZZ Release Ileum, Percutaneous Approach
0DNB4ZZ Release Ileum, Percutaneous Endoscopic Approach
0DNE0ZZ Release Large Intestine, Open Approach
0DNE2ZZ Release Large Intestine, Open Endoscopic Approach

Conversion of MS-DRGs
• At first, conversion of MS-DRGs to I-10 appeared more difficult than it turned out to be
• MS-DRGs are composed of logical relationships among lists of I-9 codes
– Conversion to I-10 leaves the logic of MS-DRGs unchanged
• Only the I-9 lists of codes that underlie MS-DRGs need to be converted
– The conversion of the I-9 code lists to I-10 code lists is straightforward
– A process of “find and replace” 
– Can be partially automated

MS-DRGs Conversion Summary
• A fixed, manageable number of lists in MS-DRGs
• The GEMs produce 95% of the mapping without any need for review
• The remaining 5% is based on MDC 6
– Need for review of the remaining MDCs is expected to steadily decrease
– As the rules derived for MDC 6 are applied to the remaining MDCs, fewer codes need clinical review

Issues Discovered 
in Converting MS-DRGs
• Overly broad I-9 procedure codes
– Lack of anatomic specificity, NOS procedures
– Require list-specific criteria for identifying the appropriate anatomic subset of PCS codes that belong on a list
• I-9 code conflicts
– When an I-10 code does not contain a distinction found in two or more I-9 codes, all the I-9 codes are mapped to the same I-10 code
• A conflict exists if the I-9 codes are in different MS-DRGs
• This is to be expected between code sets with significant differences in design and structure
Overly Broad I-9 Procedure Codes
• Should an I-9 procedure code be replaced with all associated PCS codes everywhere an I-9 code is listed?
– A PCS code may be irrelevant to a list because of its anatomic or root operation specificity
• ~200 overly broad I-9 procedure codes identified

Examples of 
Overly Broad I-9 Codes

I-9		Description
92.27	Radioactive elem implant
86.09	Skin & subq incision NEC
83.82	Muscle or fascia graft
81.96	Other repair of joint
80.19	Other arthrotomy NEC 
77.19	Bone incis w/o div NEC 
39.50	Angio oth non-coronary
39.31	Suture of artery
39.29	Vasc shunt & bypass NEC
38.21	Blood vessel biopsy
01.24	Other craniotomy
04.04	Peripheral nerve incis NEC

Solution for I-9 Overly Broad Procedure Codes
• Limit the assignment of PCS codes associated with overly broad I-9 codes to anatomic sites corresponding to each MDC

MDC 6 Example: 
MS-DRGs 356, 357, 358 Other Digestive System O.R. Procedures 
92.27 Implantation or Insertion of Radioactive Elements 
• For procedure 92.27, only 10 of the 261 PCS codes are assigned to MDC 6
I-9 Code Conflicts
• I-9 codes may contain detail not pertinent to current understanding of disease or to a PCS axis of classification
– I-9 diagnosis codes may use outmoded terminology
– I-9 procedure codes may include diagnosis information (e.g., drainage of a cyst, drainage of an abscess)
• In such cases, the I-10 code is assigned to the I-9 code that results in the most appropriate MS-DRG assignment
I-9 Code Conflicts 
Conflict: Where an I-10 code is assigned to more than one I-9 code and the I-9 codes are assigned to different MS-DRGs

I09.89 Other specified 	rheumatic heart 	diseases
		Rheumatic disease of 	pulmonary valve

398.99 	Other rheumatic heart 	diseases
	in MDC 5 DRG 314,315,316 
	Other circulatory system diagnoses 
397.1 	Rheumatic diseases of pulmonary valve
	in MDC 5 DRG 306,307 
	Cardiac congenital & valvular disorders

DRG Logic Changes
• In general, MS-DRG conversion involves replacing lists of I-9 codes without changing underlying DRG logic
• In a few cases, DRG logic for I-10 MS-DRGs must be modified in order to replicate the I-9 DRG logic
• Example: Radical Pancreaticoduodenectomy

Summary
• Conversion of ICD-9 based systems and processes to ICD-10 is straightforward
– GEMs facilitate conversion
• Conversion of MS-DRGs to ICD-10 codes well underway
– Medical DRGs converted and initial review complete
– Surgical DRGs auto-replaced by GEMs, translations being reviewed and finalized
– Appendices still to be converted
• Preliminary version slated for internal CMS review beginning October 2009
• ICD-10 MS-DRGs definitions manual to be posted on CMS website with the annual ICD-10 update at the end of 2009
• Final version of MS-DRGs using ICD-10 codes will be subject to the rule-making process

ICD-10 MS-DRG 
Definitions Manual
Format Options
ICD-10 MS-DRG Definitions Manual
• MDC 06 currently posted in two different formats
– list format
– condensed format
• Additional format options available
• Seek public feedback on preferred format
– Send comments to CMS

List Format
• Lists all ICD-10 codes with their full descriptions
Condensed Format
• Lists ICD-10 codes in condensed notation, followed by number of codes included
PCS Option: Table Format
• Lists ICD-10-PCS codes in table format, includes total number of codes
PCS Option: 

Root Operation Format
• Condensed description organized by root operation, includes total number of codes
Major Small and Large Bowel Procedures  1483 ICD-10-PCS codes

Bypass Altering the route of passage of the contents of a tubular body part 
 	Duodenum 			0D19*** 			61 codes 
 	Small Intestine Region 		0D1[AB]*** 		230 codes 
 	Large Intestine Region 	0D1[HKLMN][0348][7JKZ][4HKLMNP] 	303 codes 

Dilation Expanding an orifice or the lumen of a tubular body part 
 	Small Intestine, All 		0D78[034][DZ]Z 		6 codes 
	Duodenum 			0D79[034][DZ]Z 		6 codes 
 	Small Intestine Region 		0D7[AB][034][DZ]Z 		12 codes 
 	Ileocecal Valve 			0D7C[034][DZ]Z 		6 codes 
	Large Intestine, All 		0D7E[034][DZ]Z 		6 codes 

PCS Option: 
Body Part Format
• Condensed description organized by body part, includes total number of codes
Major Small and Large Bowel Procedures  1483 ICD-10-PCS codes
Small Intestine, All 
 	Dilation 			0D78[034][DZ]Z 		6 codes 
 	Fragmentation 			0DF8[03478]ZZ 		5 codes 
Duodenum 
 	Bypass 			0D19*** 			61 codes 
 	Dilation 			0D79[034][DZ]Z 		6 codes 
 	Excision 			0DB97ZZ  
 	Fragmentation 			0DF9[03478]ZZ 		5 codes 
Small Intestine Region 
 	Bypass 			0D1[AB]*** 		230 codes 
	Dilation 			0D7[AB][034][DZ]Z 		12 codes 
 	Fragmentation 			0DF[AB][03478]ZZ 		10 codes 
Ileocecal Valve 
	 Dilation 			0D7C[034][DZ]Z 		6 codes 
Large Intestine, All 
 	Dilation 			0D7E[034][DZ]Z 		6 codes 
	Excision 			0DBE[0348]ZZ 		4 codes 
 	Fragmentation 			0DFE[03478]ZZ 		5 codes 

Comments?
• Send feedback on the MS-DRGs I-10 definitions format to CMS
Summary
• ICD-10 MS-DRGs definitions manual to be posted on CMS website with the annual ICD-10 update at the end of 2009
• CMS ICD-10 website is
– http://www.cms.hhs.gov/ICD10/
• Final version of MS-DRGs using ICD-10 codes will be subject to the rule-making process

