Using energy from a fusion reactor to produce such synfuels as hydrogen is a challenging goal because of the special thermal requirements imposed on the blanket design. The interfacing of the tandem mirror reactor to the General Atomic thermochemical process (TCP) for hydrogen production considering two types of interfacing approaches is investigated. The first uses electrical energy to joule heat a high-temperature part of the TCP and can have an overall plant efficiency of ∼30 to 36%. The second approach uses high-temperature thermal energy to heat the high-temperature part of the TCP and has an overall plant efficiency of 43%. The trade-off between these two approaches involves consideration of overall plant efficiency versus the feasibility of developing a cost-effective, high-temperature blanket and heat transport system for long lifetime and high reliability.