Beginning in 2002, representatives of the ITPA and the experimental fusion facilities have met annually with representatives of the International Energy Agency (IEA) to encourage collaborations that address outstanding physics issues. The IEA sponsors several Implementing Agreements that foster joint collaborations. The resulting process has grown to involve all the IEA implementing agreements and nearly all tokamaks.

In the fall of each year, the ITPA, through its Topical Groups, prepares a report on the previous year's joint experiments and a proposal for a set of joint experiments for the coming year. The ITPA CC chair, assisted by the TG chairs, presents this proposal to the world's tokamak program leaders in a meeting in the December time frame. At this meeting, the joint experiments are discussed, and commitments are sought from the various tokamak program leaders. An international participant team is identified and a spokesperson defined. The tokamak leaders seek to implement these joint experiments within their normal experimental planning processes.

Since 2008 (when the ITPA came under sponsorship of ITER), there has been an increased focus on addressing remaining uncertainties in the physics related to ITER design and operation. The ITER-ITPA-IEA partnership, already having proven extremely beneficial, is expected to have a major impact on refining the plan for ITER operations for many years — well beyond the ITER Construction Phase.