My wife can no longer walk so we installed a stairlift and converted our bathtub to a walk in shower. Are these deductible and where do I list them on the return?

Yes, you can.  The key is that you need to subtract any increase in market value to the house from the cost of the improvement.  Lifts of any kind, though, are considered fully deductible.  Removing a bathtub would actually decrease the value of the house if it was the only bathtub, so that would also be fully deductible.  If you have more then one bathtub in the house, though, you would want to talk to a local appraiser to ask if your conversion improved the home value.

The possibly bad news is that these would be taken as medical expenses.  You only receive a deduction for medial expenses for the amount that exceeds 7.5% of your Adjusted Gross Income and only then if the total of all your itemized deductions exceeds your standard deduction.  With the new standard deduction for married joint couples of $24,000, you may find your itemized deductions in total are not enough to itemize.