45 C.F.R. § 84.88
Where a recipient can demonstrate that compliance with the requirements of § 84.84 would result in a fundamental alteration in the nature of a program or activity or in undue financial and administrative burdens, compliance with § 84.84 is required to the extent that it does not result in a fundamental alteration or undue financial and administrative burdens. In those circumstances where personnel of the recipient believe that the proposed action would fundamentally alter the program or activity or would result in undue financial and administrative burdens, a recipient has the burden of proving that compliance with § 84.84 would result in such alteration or burdens. The decision that compliance would result in such alteration or burdens must be made by the head of a recipient or their designee after considering all resources available for use in the funding and operation of the program or activity, and must be accompanied by a written statement of the reasons for reaching that conclusion. If an action would result in such an alteration or such burdens, a recipient shall take any other action that would not result in such an alteration or such burdens but would nevertheless ensure that individuals with disabilities receive the benefits or services provided by the recipient to the maximum extent possible.
45 C.F.R. §84.88