No consensus national standard of what constitutes a NICU exists. Some states have defined levels of care, while other states have informal or no systems for classification. The American Academy of Pediatrics has defined NICU levels of care based primarily on availability of specialized equipment and staff, but many NICUs often encompass both intensive and step-down or intermediate care. The recommended minimum standards we have written encompass Level III subspecialty care in general, rather than distinguish criteria for each sub-level.

For the purposes of this document, newborn intensive care is defined as care for medically unstable or critically ill newborns requiring constant nursing, complicated surgical procedures, continual respiratory support, or other intensive interventions.

Intermediate care includes care of ill infants requiring less constant nursing, but does not exclude respiratory support. When an intensive care nursery is available, the intermediate nursery serves as a "step down" unit from the intensive care area. When hospitals mix infants of varying acuity, requiring different levels of care in the same area, intensive care design standards shall be followed to provide maximum clinical flexibility.