The official FAR clause lists 15 safeguards, but CMMC documentation often references 17 practices. Here is why: 

CMMC inherited the DoD’s earlier mapping from the DFARS 252.204-21 “Basic Safeguarding” table, where two of the FAR requirements were split into multiple CMMC practice IDs during modeling. They are not additional requirements—just a structural carryover from the original DoD-to-NIST mapping exercise.