See main article: 2018 Davis Cup.
The Americas Zone is one of the three regional zones of the 2018 Davis Cup.
In the Americas Zone there are three different tiers, called groups, in which teams competed against each other to advance to the upper tier. Winners in Group I advanced to the World Group play-offs, along with losing teams from the World Group first round. Teams who lost their respective ties competed in the relegation play-offs, with winning teams remaining in Group I, whereas teams who lost their play-offs were relegated to the Americas Zone Group II in 2019.
Remaining nations: