Originally Posted by
bbtrvl
I'm not sure about US Citizens in NEXUS. CBP is rather vague. Perhaps due to the legal requirements of US citizens to have a passport or passport card for international travel, they can't officially endorse enrolling someone in NEXUS without one of those documents.
https://www.dhs.gov/trusted-traveler-comparison-chart is very clear; the "Passport Required" row says "No" for NEXUS and SENTRI. The interactive program selector tool also offers NEXUS if you explicitly say you don't have a passport, but removes Global Entry from the list.