A loading unit and retention band assembly including a shell and a retention band. The shell has a proximal end portion that defines an engagement window and that includes an annular surface. The retention band is disposed radially about the annular surface of the proximal end portion and includes a resilient body having first and second ends. The first end includes a resilient lock that is configured to extend through the engagement window of the proximal end portion of the shell. The resilient lock is dimensioned to releasably engage a surgical instrument.