This manuscript describes five of the most common mistakes made in developmental education programs based on the author's experiences, which include consulting at over 200 community colleges. These mistakes include failing to create a seamless transition, failing to train adjunct instructors, failing to coordinate developmental programs, failing to enforce attendance policies, and failing to ensure that the students who need the most help get it. Each mistake is discussed and followed by a description of what community college developmental programs can do to correct these mistakes.