A method and system for changing type-of-service with an associated quality-of-service in a data-over-cable system is provided. The method and system allow a cable modem or a cable modem termination system to dynamically override the statically assigned type-of-service supplied to the cable modem in a Dynamic Host Configuration Protocol (“DHCP”) initialization sequence. A selection input can request a second type-of-service that may or may not be supported by the cable modem on the cable modem termination system. If the requested second type-of-service with an associated second quality-of-service is permitted on the cable modem, the cable modem termination system dynamically changes the first type-of-service to the requested second type-of-service. Allowing a cable modem and cable modem termination system to change the statically assigned type-of-service to a second type-of-service allows the user greater flexibility for configuration cable modems in a data-over-cable system.