Canadains holding NEXUS cards often ask if they can use the card instead of their passport, especially when their passport is in the custody of an embassy being reviewed for a visa.
The answer appears to be a cautious yes, according to a somewhat vague statement by the US Customs and Border Protection Agency (Department of Homeland Security).
"The NEXUS alternative inspection program has been completely harmonized
and integrated into a single program. NEXUS members now have crossing
privileges at air, land, and marine ports of entry. Under the Western
Hemisphere Travel Initiative, the NEXUS card has been approved as an
alternative to the passport for air, land, and sea travel into the
United States for US and Canadian citizens."
We still strongly recommend that you travel with a notarized colour copy of your Canadian passport as well as your original NEXUS card if you are trying to cross at an airport.
Click here for the NEXUS card use details.