Inpatient Facility Coding & Compliance Alert

Question: Can you explain how inpatient admissions are assigned to Medicare Severity Diagnosis Related Groups (MSDRGs) 945 and 946 with the ICD-10 MS-DRGs? There are no longer diagnosis codes for encounters for rehabilitation, as was the case with ICD-9-CM codes.

Illinois Subscriber

Answer: The ICD-10 MS-DRGs version 33, effective Oct. 1, 2015, is a replication of the ICD-9-CM version 32 of the MS-DRGs. The ICD-10 MS-DRGs for rehabilitation are MS-DRGs 945 (Rehabilitation with and W CC/MCC) and 946 (Rehabilitation with and W/O CC/MCC). ICD-10-CM does not contain specific codes for encounters for rehabilitation such as ICD-9-CM codes V57.89 (Care involving other specified rehabilitation procedure) and V57.9 (Care involving unspecified rehabilitation procedure). In order to replicate the ICD-9-CM version 32 logic using ICD-10-CM and ICD-10-PCS codes, CMS developed the logic included in the MSDRG v33 Definitions Manual.

Grouper Logic: In order to be assigned to ICD-10 MS-DRG 945 or 946 you must first have a principal diagnosis from MDC 23. MS-DRGs 945 and 946 are assigned in one of two ways:

1. The encounter has a principal diagnosis code Z44.8 (Encounter for fitting and adjustment of other external prosthetic devices) or Z44.9 (Encounter for fitting and adjustment of unspecified external prosthetic device). Both of these codes are included in the list of principal diagnosis codes assigned to MDC 23.

2. The encounter has a MDC 23 principal diagnosis code and one of the rehabilitation procedure codes listed under MS-DRGs 945 and 946.

If the case does not have a principal diagnosis code from the MDC 23 list, but does have a procedure code from the list included under the Rehabilitation Procedures for MS-DRGs 945 and 946, the case will not be assigned to MS-DRGs 945 or 946. The case will instead be assigned to an MS-DRG within the MDC where the principal diagnosis code is found.

Example: The encounter has a principal diagnosis of S02.119D (Unspecified fracture of occiput, subsequent encounter for fracture with routine healing). This code is included in MDC 8. Therefore, code S02.119D and a procedure code from the MS-DRG 945 and 956 Rehabilitation Procedure list, such as F0706GZ (Therapeutic exercise treatment of neurological system — head and neck using aerobic endurance and conditioning equipment) would not lead to MS-DRG 945 and 956 because the principal diagnosis is not included in MDC 23.

Code S02.119D is included in MDC 8 as was the ICD-9-CM predecessor code of V54.19 (Aftercare for healing traumatic fracture of other bone). Therefore, these cases would be assigned to MS-DRGs 559 – 561 (Aftercare, musculoskeletal system and connective tissue w MCC,  and without CC/MCC within MDC 8.