ICD-10-CM > P00-P96 > P05-P08 > P07 > P07.2 > P07.22 P07.22 Extreme immaturity of newborn, gestational age 23 completed weeks Billable/Specific Copy Code Copy Description Applicable To Extreme immaturity of newborn, gestational age 23 weeks, 0 days through 23 weeks, 6 days