Most people who deduct mileage against their taxes for business and medical purposes do not do it properly. The IRS requires “contemporaneous” notes regarding your mileage. The old method of “what was my odometer on Jan 1 and Dec 31” isn’t going to work. In taking deductions for mileage you must answer the following for the IRS:
Who you went to see,
What you saw them for,
When you went,
Where you went,
Why you went,
and How you got there (and how many miles it was).