There are over 135,000 deaf/hard of hearing students enrolled in postsecondary institutions in the U.S. However, deaf students who use sign language may not be aware of their sign language skills, resulting in accommodations that do not provide full access to postsecondary course content and reduced degree completion rates compared to their typically hearing peers. We documented the receptive and expressive ASL skills and self-ratings of 59 incoming deaf college students. Then we developed and implemented a five-week high-dosage ASL intervention with a cohort of 14 students using a pretest-posttest design. About half of the cohort improved across ASL assessments after the intervention, although group mean score changes were not statistically significant. Students accurately self-rated their receptive and expressive sign language skills based on their assessment performance. We present suggestions and implications for ASL instruction at the postsecondary level to promote college readiness.