<prompt> Human: Hi PF,I got a letter of audit from the IRS last week requesting the proof of the deductions that I claimed in 2013. The deductions I claimed are my fathers medical bill 20,000 due to his bypass surgery. Im no longer on talking terms with my father and I paid him cash i.e I didnt write the check to the hospital, instead, the check was written to my father who in turn paid the hospital.1 Is there any other way to prove this to the IRS?2 If I agree to pay back the tax refund penalty, can I ask for an installment plan?Thanks!  <response>: I dont think that 20,000 is deductible unless you claimed your father as a dependent. If you did, I cant see how to prove it other than getting paperwork of the transaction and hospital billsstatements.You should ask the IRS about 2, or consult a tax attorney. 