What is the correct standard mileage rate for medical-related car expense calculations? IRS instructions list it as 18 cents, but Turbo Tax lists it as 17 cents.

Page A-1 of IRS Schedule A Instructions states"The standard mileage rate allowed for operating expenses for a car when you use it for medical reason increased to 18 cents a mile."  Turbo Tax' s Medical Expense Worksheet Line 9b lists it as 17 cents a mile.  So which is it?