Because it has a very small range on a single island, and because of the introduction of a parasitic fly which kills the nestlings, the International Union for Conservation of Nature has rated the medium tree finch as "critically endangered".

This species is only found on Floreana Island at elevations above 250 meters in moist highland forest habitats.

The medium tree finch is threatened by introduced predators such as rats, mice, cats and the smooth-billed ani, as well as habitat loss, which has occurred through clearance for agriculture.

Parasitic larvae of this fly live in the nest material and feed on the blood and body tissues of nestlings.

Because of this, and because it has a very small range on a single island, the International Union for Conservation of Nature has rated the medium tree finch as "critically endangered".