In January 2009, the American Library Association (ALA) completed a ten-year reexamination of the core competences needed by professional librarians graduating from ALA-accredited institutions. The ALA's "Core Competences of Librarianship" encompass the basic knowledge expected of all graduates in all specializations. The core beliefs and policies defined in the ALA document give support to the specialized American Association of School Librarians (AASL) policies, as well as specialized policies from other divisions, and form a solid foundation for encouraging best practices in all types of libraries. The "School Librarian's Bill of Responsibilities" (Debbie Abilock, Kristin Fontichiaro, and Judi Moreillon) frames the emerging standards and position statements in the professional practice and daily activities of school librarians. At the same time, the Bill of Responsibilities reflects the Competences. This article first lists the responsibilities of the 21st-century school librarian and then describes ALA's core competences of librarianship. It also compares the "School Librarian's Bill of Responsibilities" with "ALA's Core Competences of Librarianship."