Head start Education And Development Workforce Advancement and Yield Act or the HEADWAY Act This bill allows some teachers in Early Head Start programs to teach while in the process of earning their Child Development Associate (CDA) credential and completing training. Currently, the Department of Health and Human Services (HHS) must ensure that all teachers providing direct services to children and families in Early Head Start centers (1) have a minimum of a CDA credential and have been trained in early childhood development, and (2) have been trained in early childhood development with a focus on infant and toddler development. The bill revises this requirement by requiring at least one teacher per classroom (instead of all teachers) to have a CDA credential and training. In particular, the bill requires HHS to ensure that (1) each additional teacher providing direct services to children and families is in the process of earning a CDA credential and completing training, and (2) the Early Head Start agency provides a mentor to oversee the progress and guide the work of a teacher who is in the process of earning a CDA credential and completing training.