Inpatient Facility Coding & Compliance Alert

Question: Can you explain how inpatient admissions are assigned to Medicare Severity Diagnosis Related Groups (MS-DRGs) 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.

Texas 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 and 946 (Rehabilitation with and without 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 MS-DRG v33 Definitions Manual.

MS-DRGs 945 & 946 (Rehabilitation with and without CC/MCC) 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 & 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 & 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 a 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 & 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 & 956 since 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 with MCC, with CC, and without MCC/CC) within MDC 8.