In short, no. According to the National Center on Education Statistics (NCES)  only 26% of students with disabilities enrolled in postsecondary institutions use disability services. The source of this data is the U.S. Department of Education, NCES, 1999-2000 National Postsecondary Student Aid Study.
There are many reasons why individuals with disabilities choose not to use disability services. Some do not need accommodations (for example, a student who uses a cane for mobility but can independently climb small flights of stairs may be fully independent in her mobility on campus). Some may not want to identify themselves as having a disability. And some students may be unaware of the availability of disability services.
-  National Center on Education Statistics (NCES)