Importance: Children exposed to substance use during pregnancy have increased health needs but whether these are influenced by engagement in out-of-home care is uncertain.

Question: Does the increase in health care needs among children exposed to substance use during pregnancy vary by engagement in out-of-home care?

Findings: In this cohort study, children exposed to substance use during pregnancy with or without neonatal abstinence syndrome were at higher risk of adverse birth outcomes and long-term costs than children who were not exposed but a reduction in cost was associated with any out-of-home care contact.

Meaning: Increased support and timely access to services could mitigate the higher readmission risk and cost associated with substance use during pregnancy.