R65.21Severe sepsis with septic shock

R65.21 is the ICD-10-CM diagnosis code for severe sepsis with septic shock. It belongs to category R65 (symptoms and signs specifically associated with systemic inflammation and infection), block R50-R69 (general symptoms and signs) and chapter 18 (symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within R65.2 (severe sepsis), R65.21 is specifically for severe sepsis with septic shock. Related codes cover without septic shock (R65.20).

Don't report R65.21 together with the conditions in its Excludes1 note: postprocedural septic shock (T81.12-).

As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 870 (Septicemia or Severe Sepsis with MV >96 Hours, relative weight 6.9408), DRG 871 (Septicemia or Severe Sepsis without MV >96 Hours with MCC, relative weight 1.932) and DRG 872 (Septicemia or Severe Sepsis without MV >96 Hours without MCC, relative weight 1.0066), in MDC 18 (Infectious and Parasitic Diseases, Systemic or Unspecified Sites), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is not acceptable as the principal diagnosis for an inpatient stay; it may be reported as a secondary diagnosis.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 785.52 (septic shock) and 995.92 (severe sepsis).