Retention (i.e., response maintenance) is rarely the primary variable of interest when examining skill acquisition procedures. Trial presentation type (i.e., acquisition targets only vs. interspersal of previously acquired targets) within discrete-trial training is one procedural component that researchers have hypothesized may affect performance on follow-up retention probes. The present study compared single-task presentation (varied instruction) and task interspersal procedures with regard to retention of a mastered task. We taught four children two skills so that retention of the mastered skill (Skill 1) could be assessed during ongoing instruction of a new skill (Skill 2) using varied instruction versus task interspersal. Findings demonstrated equivalency of varied instruction and task interspersal. Results support that frequent rehearsal of a skill acquisition program without consequences is equivalent to ongoing instruction with consequences. Findings suggest instructors should program follow-up probes of previously mastered content into or between sessions, especially when utilizing single-task trial arrangements that do not incorporate such.