Non-Intrusive Inspection Expansion Act This bill requires U.S. Customs and Border Protection (CBP) to increase its use of nonintrusive inspection systems to scan passenger and commercial vehicles at land ports of entry. Beginning no later than September 30, 2026, CBP must use such systems at land ports of entry to scan at least (1) 40% of passenger vehicles and 90% of commercial vehicles entering the United States, and (2) 10% of all vehicles exiting the United States. The Government Accountability Office must report to Congress on the use of such systems, including an assessment of their effectiveness.