What is the phone number for icma customer service? 1-800-669-7400. Representatives are available: Weekdays: 8:30 a.m. - 9:00 p.m. Eastern Time. ICMA-RC's Self-Service phone line is available: 24-hours, 365 days a year.How do i contact icm for emergency situations? For emergency situations, we are here for you day and night, including holidays. Let's work together: General Inquiries: +1 (316) 796 0900. [email protected]. 24-hour plant support: [email protected]. +1 (877) 456 8588. Offices:How do i get a preauthorization from icm? We utilize advanced and innovative technology that allows us to easily connect and partner with TPA’s throughout the United States. To submit a preauthorization request over the phone, please call the direct line at: 800-862-3338. ICM was founded in 1990 by industry pioneers in healthcare management, Sherry Chenell and Kris Hallock.