P56.0Hydrops fetalis due to isoimmunization

P56.0 is the ICD-10-CM diagnosis code for hydrops fetalis due to isoimmunization. It belongs to category P56 (hydrops fetalis due to hemolytic disease), block P50-P61 (hemorrhagic and hematological disorders of newborn) and chapter 16 (certain conditions originating in the perinatal period). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within P56 (hydrops fetalis due to hemolytic disease), P56.0 is specifically for hydrops fetalis due to isoimmunization. Related codes cover other and unspecified hemolytic disease (P56.9).

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 791 (Prematurity with Major Problems, relative weight 4.1075) and DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), in MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period), 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 773.3 (hydrops fetalis due to isoimmunization).