B33.0Epidemic myalgia

B33.0 is the ICD-10-CM diagnosis code for epidemic myalgia. It belongs to category B33 (other viral diseases, not elsewhere classified), block B25-B34 (other viral diseases) and chapter 1 (certain infectious and parasitic diseases). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within B33 (other viral diseases, not elsewhere classified), B33.0 is specifically for epidemic myalgia. Related codes cover Ross River disease (B33.1), viral carditis (B33.2), retrovirus infections, not elsewhere classified (B33.3), Hantavirus (cardio)-pulmonary syndrome [HPS] [HCPS] (B33.4) and other specified viral diseases (B33.8).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 193 (Simple Pneumonia and Pleurisy with MCC, relative weight 1.2825), DRG 194 (Simple Pneumonia and Pleurisy with CC, relative weight 0.7888) and DRG 195 (Simple Pneumonia and Pleurisy without CC/MCC, relative weight 0.6063), in MDC 04 (Diseases and Disorders of the Respiratory System), 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 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 074.1 (epidemic pleurodynia).