Under Oklahoma law (O.S. 68 Section 2358 (D) (4)) an income tax deduction is available to individuals for the cost of modifications to a personal vehicle, home or workplace to compensate for the disability. To claim the deduction an individual must be an Oklahoma resident and have a physical disability which constitutes a substantial handicap to employment. Veterans certified by the VA as having a service-connected disability are conclusively presumed to be eligible for the deduction. Social Security Administration determination that a person is disabled may also serve as verification of a disability that is a handicap to employment. The Tax Commission may also consider other documentation of disability, such as a doctor's letter and/or agency letter that verifies a handicap to employment. Documentation of the expenses incurred must also be provided by the individual.

https://www.ok.gov/tax/Individuals/Motor_Vehicle/Tag,_Tax,_Title_&_Fees/...