Yes the conversion cost is deductible as a medical expense, subject to being an itemized deduction and the 7-1/2% of AGI rule*.  You do not need any paperwork at the time you file your tax return. Save the receipt, in case of an audit. The deduction is claimed on schedule A, along with your other itemized deductions. 

*For example, if you have an adjusted gross income of $45,000 and $5,475 of medical expenses, you would multiply $45,000 by 0.075 (7.5 percent) to find that only expenses exceeding $3,375 can be deducted. This leaves you with a medical expense deduction of $2,100 (5,475 - 3,375)