This article-the third in a 6-part series-examines the status of the DO degree in the first 3 decades of the 20th century. This time was an era when osteopathic practitioners established other colleges, developed state and national organizations, upgraded the length and breadth of curricula, and sought to secure licensure laws commensurate with their expanded education. During this period, osteopathic practitioners debated whether the DO degree was the most appropriate degree for their colleges to award or whether the MD degree alone or in conjunction with the DO degree better signified to lawmakers and the public their expanded academic training. At the end of this period it appeared likely that the DO degree would continue to be the sole designation by which osteopathic physicians would identify themselves in continuing their fight to obtain further legal rights and privileges.