ICD-10-CM > P00-P96 > P76-P78 > P77 P77 Necrotizing enterocolitis of newborn Non-Billable/Non-Specific Codes P77.1Stage 1 necrotizing enterocolitis in newbornP77.2Stage 2 necrotizing enterocolitis in newbornP77.3Stage 3 necrotizing enterocolitis in newbornP77.9Necrotizing enterocolitis in newborn, unspecified