A system and method for protecting access to metadata based on package membership. The system creates at least one customized metadata type for a first software package and assigns a package protected access mode to control access to the at least one customized metadata type by respective components of one or more software packages. The system denies access to the at least one customized metadata type, according to the package protected access mode, by at least one component of a second software package that shares a namespace with the first software package.