Existing evidence suggests that offenders tend not to specialize in sexual offending in general but that there is some specialization in particular types of sexual offending. This study examined the sexual histories and reoffending of a large, national data set of offenders convicted of a sexual offense and managed in England and Wales by the National Offender Management Service (N = 14,804). The study found that specialization in sexual offending compared to nonsexual offending was most evident for offenders with convictions for accessing indecent images. We also found considerable evidence of specialization within sexual offending, most notably for noncontact offenders, especially again indecent images offenders. Crossover between sexual offense types was very rare for those with contact adult offenses and for noncontact offenders although those with child contact offenses sometimes crossed over to indecent images reoffending. If specialization within sexual offending exists, the use of single risk assessment instruments to predict all types of sexual recidivism may be less effective than previously assumed. A comparison of different prediction models indicated that some items presently used in one-size-fits-all risk tools to predict any sexual reoffending only effectively predict certain subtypes of sexual offending. Statistically there appear to be some potential benefits to creating specialist risk predictors for different subtypes of offending, but further work is needed to justify the implementation demands that would be caused by abandoning one-size-fits-all tools.