@--zimmermanohio
you don’t send any proof with your tax return. Keep documents for at least three years in case of audit. What you will need is to prove the two parts of the medical expense deduction for home improvement.
1. The improvement was medically necessary.
2. The improvement did not increase the value of your home.
(Improvements that increase the value of your home are treated as adjustments to cost basis. They are not deductible medical expenses at the time you pay them, but they might reduce the capital gains tax that you will owe when you sell the home.)
To show that the improvement did not increase the value of your home, you might think about getting a real estate appraisal, or an affidavit from an expert appraiser discussing the value of medical improvements, or you might do your own investigation of your local real estate market to see if you can find a similar homes with and without an elevator that sold for the same price.
