The Homeland Enterprise consists of a vast series of formal and informal relationships between federal departments and agencies; state, local, tribal, and territorial (SLTT) entities; and the private sector. Each of these entities and relationships – some long-established, others newly emergent – contribute to the body of information that is collected and analyzed to produce the intelligence necessary to protect the U.S. homeland. INSA’s Homeland Security Intelligence Council (HSIC) conducted interviews with more than 40 experts for their perspectives on the progress of the Enterprise and its remaining challenges 15 years after September 11, 2001, and five years after its first white paper on the topic.