It is the International Association for Contract & Commercial Management. Members can obtain certifications in the profession of contract management. It is a global organization with approaching 10,000 members.
They are both professional organizations for contract management. The NCMA tends to focus on US contracts with the government. The IACCM is an international organization that supports members on both sides of the agreements. Both provide certifications for those that meet the requirements. I am a member of the IACCM and am certified as a Contracts Expert.