Recent case law within and outside the school context has revised or refined various concepts concerning eligibility and other K-12 issues under Section 504 and the Americans with Disabilities Act (ADA). Ten case lessons are described in this paper, seven of which are: (1) The frame of reference for determining "substantially limits" in the definition of disability is horizontal and national; (2) moreover, the determination of "substantially limits" is with, not without, mitigating measures; (3) providing a "504 Plan" for a student who may be eligible under the Individuals with Disabilities Education Act (IDEA) can lead to costly consequences; (4) conversely, providing a "504 Plan" as, in effect, a consolation prize for a student who is not eligible under the IDEA may also have costly consequences; (5) the majority standard for liability under Section 504 and the ADA appears to be bad faith or gross misjudgment; (6) with a limited exception, school officials in their individual capacity may not be liable under Section 504 or the ADA; and (7) the most recent cases may possibly signal a trend in favor of student-athletes in Section 504 or ADA cases against rules, without waivers, of interscholastic athletic associations. Rulings in other recent court decisions are given honorable mention at the end of the paper. (RT)