Mallinckrodt PLC recently disclosed that it did not make the interest payments due on its 11.5% first-lien senior secured notes maturing 2028 and 10% second-lien senior secured notes maturing 2029 in their 30-day grace periods. However, the company remains current on its other debt obligations. We view these missed payments as tantamount to a default under our criteria, given that the lenders did not receive the value they were initially promised in a timely manner (notwithstanding their entry into a forbearance agreement). Therefore, we lowered our issuer credit rating on Mallinckrodt to 'SD' (selective default) from 'CCC'. At the same time, we lowered our issue-level rating on the affected 2028 secured notes to 'D' from 'CCC+' and our issue-level rating