29 C.F.R. § 1630.9 : Labor — REGULATIONS RELATING TO LABOR — EQUAL EMPLOYMENT OPPORTUNITY COMMISSION — REGULATIONS TO IMPLEMENT THE EQUAL EMPLOYMENT PROVISIONS OF THE AMERICANS WITH DISABILITIES ACT — Not making reasonable accommodation

(a) It is unlawful for a covered entity not to make reasonable accommodation to the known physical or mental limitations of an otherwise qualified applicant or employee with a disability, unless such covered entity can demonstrate that the accommodation would impose an undue hardship on the operation of its business.
(b) It is unlawful for a covered entity to deny employment opportunities to an otherwise qualified job applicant or employee with a disability based on the need of such covered entity to make reasonable accommodation to such individual's physical or mental impairments.
(c) A covered entity shall not be excused from the requirements of this part because of any failure to receive technical assistance authorized by section 507 of the ADA, including any failure in the development or dissemination of any technical assistance manual authorized by that Act.
(d) An individual with a disability is not required to accept an accommodation, aid, service, opportunity or benefit which such qualified individual chooses not to accept. However, if such individual rejects a reasonable accommodation, aid, service, opportunity or benefit that is necessary to enable the individual to perform the essential functions of the position held or desired, and cannot, as a result of that rejection, perform the essential functions of the position, the individual will not be considered qualified.
(e) A covered entity is required, absent undue hardship, to provide a reasonable accommodation to an otherwise qualified individual who meets the definition of disability under the "actual disability" prong (§ 1630.2 ), or "record of" prong (§ 1630.2 ), but is not required to provide a reasonable accommodation to an individual who meets the definition of disability solely under the "regarded as" prong (§ 1630.2 (iii)).

29 C.F.R. §1630.9

56 FR 35734, 7/26/1991, as amended at 76 FR 17002, 3/25/2011