Yes, with qualifications. The main purpose of the trip has to be charitable service. Also, any costs for recreation or personal activities are not deductible.
The IRS says: Generally, you can claim a charitable
contribution deduction for travel expenses necessarily incurred while you are away from home
performing services for a charitable organization only if there is no significant element of personal pleasure, recreation, or vacation in the
travel. This applies whether you pay the expenses directly or indirectly. You are paying the expenses indirectly if you make a payment to the
charitable organization and the organization
pays for your travel expenses.
The deduction for travel expenses won't be
denied simply because you enjoy providing
services to the charitable organization. Even if
you enjoy the trip, you can take a charitable
contribution deduction for your travel expenses
if you are on duty in a genuine and substantial
sense throughout the trip. However, if you have
only nominal duties, or if for significant parts of
the trip you don't have any duties, you can't de
duct your travel expenses.
