@janeisen79 ,
1. Click Reports from the left sidebar.
2. Type Customer Contact List in the Find Report by Name box.
3. Click Customize (upper right)
4. Click Change Columns and tick Taxable. You may also want to tick Tax Rate... if any inconsistent or incorrect taxable status setup exists, that will help to bring it to your attention.
5. Run report.
6. Click Sort (far left, above report title)
7. Choose Taxable from pulldown menu.
8. Toggle Descending Order... this will list all of your tax exempt customers first.
9. Export.