2018 Fed Cup Americas Zone Group I – play-offs

The play-offs of the 2018 Fed Cup Americas Zone Group I were the final stages of the Group I Zonal Competition involving teams from the Americas. Using the positions determined in their pools, the seven teams faced off to determine their placing in the 2018 Fed Cup Americas Zone Group I. The winner of the promotion play-off advanced to World Group II play-offs, and the losers of the relegation play-off were relegated down to the Americas Zone Group II.

Promotion play-off
The first placed teams of the two pools were drawn in head-to-head rounds. The winner advanced to the World Group II play-offs.

Third place play-off
The runner-up teams of the two pools were drawn in head-to-head to determine the third and fourth placings.

Relegation play-offs
The bottom team of Pool A and the third placed team of Pool B were drawn in head-to-head. The loser was relegated down to Americas Zone Group II in 2019. The last placed team of Pool B (Guatemala) was automatically relegated.

Final placements

 *  was promoted to the 2018 Fed Cup World Group II play-offs.
 * ' and ' were relegated to Americas Zone Group II in 2019.