Set Up Your HSA Account Complete the Form Download and complete the HSA set-up form with Interra Credit Union. Fax or mail the form to the contact information located at the bottom of the PDF. Open an Account Call Interra at (574) 534-2506 or (888) 432-2848 to open your account once the set-up form has been completed and submitted. Share Your Account Number Once your account is open, notify the Goshen benefits team with your Interra-provided account number so that contributions can begin. Download the Form