The Constitution Annotated online now includes updated content under Article I, Section 8, Clause 18 discussing the necessary and proper clause.
[The Congress shall have Power . . . ] To make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States, or in any Department or Officer thereof.
ArtI.S8.C18.3 The Necessary and Proper Clause: Doctrine and Practice