This study examined the relationship between sentence length and time to commission of serious and violent disciplinary infractions by female inmates divided into short (2 years or less), intermediate (2-8 years), and long-term (8 or more years) groups. Relying on the intermediate-term group as a referent, a Cox regression model demonstrated that short-term inmates were most likely, and long-term inmates least likely, to commit serious and violent infractions across monthly time intervals during the 2-year study period. All three groups exhibited a low base rate of violent behavior directed toward inmates and staff. Predictors associated with the time to commission of serious and violent acts included age, education, mental health, and custody level. Findings point to the potential for over-classification to more secure custody assignments for some inmates, particularly for long-term female prisoners. Policy, institutional, and clinical implications are discussed, including the need for specialized programming and mental health treatment.