According to the AviList checklist v2025 (link), the taxon comprises two species in two genera in a single family, Cariamidae, confined to South America:

Timetree of extant Cariamidae according to Stiller et al. (2024), with the distribution of each species being indicated by the colour-code used throughout this website (Distribution code). 

Traditional genus-level classification of extant Cariamiformes following AviList checklist v2025. (link) 

Bibliography

Stiller J, Feng S, Chowdhury AA, Rivas-González I, Duchêne DA, Fang Q, Deng Y, Kozlov A, Stamatakis A, Claramunt S, Nguyen JMT, Ho SYW, Faircloth BC, Haag J, Houde P, Cracraft J, Balaban M, Mai U, Chen G, Gao R, Zhou C, Xie Y, Huang Z, Cao Z, Yan Z, Ogilvie HA, Nakhleh L, Lindow B, Morel B, Fjeldså J, Hosner PA, da Fonseca RR, Petersen B, Tobias JA, Székely T, Kennedy JD, Reeve AH, Liker A, Stervander M, Antunes A, Tietze DT, Bertelsen M, Lei F, Rahbek C, Graves GR, Schierup MH, Warnow T, Braun EL, Gilbert MTP, Jarvis ED, Mirarab S, and Zhang G (2024), Complexity of avian evolution revealed by family-level genomes, Nature 629, 851-860. (free reading)