Parenteral nutrition (PN) is one of the most complex drug prescriptions available, containing 20-40 ingredients. The Institute for Safe Medication Practice (ISMP) defined PN as a high-alert medication, meaning a medication that may heighten the risk of significant patient harm. Due to limited intravenous access, medications may need to be co-infused (y-sited) with PN admixtures. INS and ASPEN both recommend that medications not be co-infused with PN admixtures without consultation with a pharmacist regarding compatibility and stability. In this session, we will review considerations for compatibility and stability of medication co-administration with PN. We will also discuss a practical approach to monitoring and assessing y-site compatibility with PN.