Is a Generac standby whole house generator tax deductible if I require a CPAP machine?

A whole-house generator is most likely not deductible as a medical expense in your situation.  There are a number of less expensive alternatives available that would sufficiently power your CPAP device alone, and not your whole house.  The cost of one of these lower-priced CPAP machine-specific alternatives would presumably be eligible for a medical deduction. 

 

But to deduct  even a portion of the cost of a whole-house generator, you'd need to make two calculations:

 

1. Any deduction that you might be eligible for would have to be reduced by any amount that the property value of your home might be increase by the improvement.  See Worksheet A, Capital Expense Worksheet in the IRS' Publication 502 (2023), Medical and Dental Expenses for guidance on how this amount is figured.
2. Then, of that amount, you could only claim a portion that could reasonably be allocated to powering your CPAP machine, as opposed to the entirety of your home.  A small percentage, to be sure.

@Bgoat 

[Edited 1/18/2024 | 1:00 pm CST]

I’m not convinced.  Loss of CPAP for one night is rarely life threatening, battery backups are available as well, and the whole house generator also supplies non-medical household needs.  Additionally, even if allowable, it is only allowable to the extent it does not increase the fair market value of the home.  If it increase the value of the home (makes it easier to sell or raises the selling price) then it is a capital improvement that adds to the cost basis and is not an immediate medical expense deduction.