Installation Voting Assistance Office (IVAO) is located at Military & Family Readiness Center 5837 D Avenue Building 150 Hill AFB, UT 84056-5720, , . Installation Voting Assistance Office (IVAO) can be reached by their main phone number at (801) 777-4681. Alternatively, you can reach Installation Voting Assistance Office (IVAO) by phone at (801) 777-5736. The listed DSN line is 312-777-4681. Visit the Installation Voting Assistance Office (IVAO) website by clicking here.