P55.0Rh isoimmunization of newborn

P55.0 is the ICD-10-CM diagnosis code for Rh isoimmunization of newborn. It belongs to category P55 (hemolytic disease of newborn), 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 P55 (hemolytic disease of newborn), P55.0 is specifically for Rh isoimmunization of newborn. Related codes cover ABO isoimmunization of newborn (P55.1), other hemolytic diseases of newborn (P55.8) and unspecified (P55.9).

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 794 (Neonate with Other Significant Problems, relative weight 1.4935), 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 773.0 (hemolytic disease of fetus or newborn due to Rh isoimmunization).