Update: I ended calling the IRS hotline for international tax payers. I was connected almost immediately with almost no wait. The IRS rep said to report the taxes withheld in 1040 Box 25c which is used for 'Other Tax Withholding'--I have not found a way to do this automatically in Turbotax, but since I am using the desktop version, I was able to manually enter in the tax worksheet. The rep said to submit a copy of the foreign broker statement showing the taxes withheld as well as a statement/explanation referencing the applicable tax treaty and dividend withholding specified in said treaty. The rep even guided me to the treaty document locations on the IRS website.
