The majority of evidence-based psychological treatments (EBTs) are packaged as manuals that provide guidance regarding when and how to deliver specific interventions (e.g., cognitive restructuring, exposure). However, clinical practice regularly necessitates flexibility in the timing and delivery of treatment strategies. Indeed, research on the dissemination and implementation of EBTs has highlighted the need to adapt these treatments to fit the needs of specific settings or patient populations. Adapting a treatment also means changing it from its original, evidence-based format, raising questions about how much or in which ways a treatment can be altered before it is no longer reflective of the original EBT. The purpose of this article is to discuss factors that contribute to the challenge of adapting EBTs, highlight considerations for clinicians with regard to modifying EBTs, and propose directions for future research that can provide guidelines for adapting EBTs in the future. (PsycInfo Database Record (c) 2022 APA, all rights reserved).