Tags are a great way to organize your contacts in Mailchimp
After you've set up your Mailchimp Integration, you may want to add tags to the supporters syncing through to Mailchimp. To do this, follow the steps below:
1) Navigate to your tool, and go to Edit -> Advanced -> CRM Integrations -> Edit Mailchimp API
2) Once here, enter in your tag(s) in the Tags/Segments field. Make sure to separate your tags with a comma, leaving no spaces before/after your tag.