Customs exemption for patient assistance programmes permits duty-free import of specified drugs subject to compliance. Imports of drugs under Chapter 30 for supply under specified Patient Assistance Programmes are exempt from customs duty provided the sponsoring pharmaceutical company supplies the drugs free to patients, furnishes an undertaking to the jurisdictional Customs officer to maintain records (patient details, identity and residence proofs, diagnosis and dosage, and imported/consumed drugs), ensures use solely for the programme, and agrees to pay duty with interest in case of non compliance.