Employers are not required to implement any reasonable accommodation that would present an undue hardship on the business. Undue hardship means that the accommodation would be unduly costly, extensive, substantial or disruptive, or would fundamentally alter the nature of operation of the business. Factors to be considered include the cost of the accommodation, the size and financial resources of the employer, and the nature and structure of the employer's business. An employer is not required to lower production standards or eliminate essential job functions to implement a reasonable accommodation. 42 U.S.C. § 12111(10).

If an employer is part of a larger organization, the structure and assets of the larger organization would be considered when determining if an accommodation is an undue hardship.  Larger employers are usually expected to make accommodations that require greater effort and expense than would be required of a smaller employer.

Employers should look for outside funding when reasonable accommodations are costly.  Vocational rehabilitation agencies may provide funds and the cost of providing accommodations can be offset by state and federal tax credits or deductions.  Also, the individual with the disability should be given the opportunity to provide the accommodation or help pay for an accommodation that creates an undue hardship on an employer.

Employers are liable for contractual relationships. 29 C.F.R. § 1630..6.

Under Title III of the ADA, if your business is a place of public accommodation then you must provide accessibility to the general public. Title III also requires places of public accommodation and commercial facilities to provide accessibility during new construction or renovation.