Knowledge Base Article

The FY 2024 IPPS Proposed Rule (CMS-1785-P) was issued by CMS April 10, 2023. This article focuses on proposed changes to Medicare Severity Diagnosis-Related Group (MS-DRG) classifications in Major Diagnostic Categories (MDCs) 02, 04, and 06 (Diseases and Disorders of the Eye, Respiratory System, and Digestive System, respectively).

MDC 02: Diseases and Disorders of the Eye: Retinal Artery Occlusion

A request was made to review the MS-DRG assignment of cases involving central retinal artery occlusion (CRAO). The assertion was that CRAO is a form of acute ischemic stroke which occurs when a vessel supplying blood to the brain is obstructed and there is growing recognition of this diagnosis as a vascular neurological problem. New evidence outlines treatment of patients with CRAO with acute stroke protocols, specifically with intravenous thrombolysis or hyperbaric oxygen therapy, to improve outcomes.

Based on this request, data analysis and examining clinical considerations, CMS is proposing to:

• Reassign ICD-10-CM diagnosis codes H34.10, H34.11, H34.12, H34.13, H34.231, H34.232, H34.233, and H34.239 from MDC 02 MS-DRG 123 to MS-DRGs 124 and 125,
• Add procedure codes describing the administration of a thrombolytic agent listed in this section of the proposed rule to MS-DRG 124,
• As part of the logic for MS-DRG 124, designate the administration of thrombolytic agent codes as non-O.R. procedures affecting the MS-DRG, and
• Change the titles of MS-DRGs 124 and 125 from “Other Disorders of the Eye, with and without MCC, respectively,” to “Other Disorders of the Eye with MCC or Thrombolytic Agent, with without MCC, respectively” to better reflect the assigned procedures.

MDC 04: Diseases and Disorders of the Respiratory System: Ultrasound Accelerated Thrombolysis for Pulmonary Embolism

A request was made to reassign cases reporting ultrasound accelerated thrombolysis (USAT) with administration of thrombolytic(s) for the treatment of pulmonary embolism (PE) from MS-DRGs 166, 167, and 168 (Other Respiratory O.R. Procedures with MCC, with CC, and without CC/MCC, respectively) to MS-DRGs 163, 164, and 165 (Major Chest Procedures with MCC, with CC, and without CC/MCC, respectively).

CMS believes clinical and data analyses support creating a new base MS-DRG for cases reporting a principal diagnosis of PE and USAT or standard catheter directed thrombolysis (CDT) procedures with or without thrombolytics and are proposing new base MS-DRG 173 (Ultrasound Accelerated and Other Thrombolysis with Principal Diagnosis of Pulmonary Embolism).

MDC 04: Respiratory Infections and Inflammations Logic

There are two logic lists for case assignment to MS-DRGs 177, 178, and 179 (Respiratory Infections and Inflammations with MCC, with CC, without CC/MCC, respectively). All diagnosis codes in the first logic list are designated as MCCs.

Currently, if the principal diagnosis is from the second logic list and any of the diagnoses from the first logic list are also on the claim, the case would be assigned to MS-DRG 177. This is inconsistent with how other similar logic lists function in the ICD-10 grouper software. Therefore, CMS is proposing to correct the logic for cases assigned to MS-DRG 177 by excluding the 15 diagnosis codes in the first logic list from acting as an MCC when reported as a secondary diagnosis when the principal diagnosis is from the second logic list.

MDC 06: Diseases and Disorders of the Digestive System: Appendicitis

ICD-10-CM diagnosis codes K35.20 (Acute appendicitis with generalized peritonitis, without abscess) and K35.21 (Acute appendicitis with generalized peritonitis, with abscess) will no longer be effective October 1, 2023. At that time, six new diagnosis codes describing acute appendicitis with generalized peritonitis, with and without perforation or abscess will become effective. The new codes are proposed for assignment to MS-DRGs 371, 372, and 373 (Major Gastrointestinal Disorders and Peritoneal Infections with MCC, with CC, and without MCC/CC, respectively).

CMS notes that clinically both localized and generalized peritonitis in association with an appendectomy require the same level of patient care and believe the distinction between “complicated” versus “uncomplicated” is no longer meaningful regarding resource consumption. Therefore, CMS is proposing to delete MS-DRGs 338, 339, 340, 341, 342, and 343 and proposing to create new MS-DRGs 397, 398, and 399 (Appendix Procedures with MCC, with CC, and without CC/MCC, respectively). The new MS-DRGs would no longer require a diagnosis in the definition of the logic for case assignment.

CMS is accepting comments through June 9, 2023.