Factors were explored that predicted whether teachers sustained the use of a validated reading intervention. Seventy-three teachers from 37 schools in 3 states were asked in interviews whether they continued to use Kindergarten Peer Assisted Learning Strategies (KPALS) 1 year after their involvement in the program. A logistic regression model was created with teachers' yes/no responses as the dependent variable and with predictors identified as important to sustainability. Findings were consonant with current theoretical models of sustainability. The logistic regression model captured many key elements of teachers' decisions to sustain. Strongest predictors were teacher perceptions of the effectiveness of KPALS and degree of external technical support given them. (Contains 6 figures and 4 tables.)