Vocabulary knowledge provides a critical foundation for later reading comprehension. Children with limited vocabularies and background knowledge often need many opportunities to learn a new word. One effective way to promote vocabulary acquisition for young children is to provide opportunities for children to learn new words throughout classroom routines. Activity-Based Intervention, an early childhood teaching approach, can be used as a framework for planning and implementing vocabulary instruction across planned, child-directed, and routine activities like science and math activities, free play during center time, and mealtimes. By using these underutilized times of the day for instruction, and by adapting instructional strategies and words taught to meet the needs of individual learners, early childhood educators can provide rich vocabulary instruction to all young children. (author abstract)