ICD-10-CM > P00-P96 > P05-P08 > P07 > P07.2 > P07.26 P07.26 Extreme immaturity of newborn, gestational age 27 completed weeks Billable/Specific Copy Code Copy Description Applicable To Extreme immaturity of newborn, gestational age 27 weeks, 0 days through 27 weeks, 6 days