Early-Stage Researchers must, at the time of recruitment by the host organisation, be in the first four years (full-time equivalent research experience) of their research careers and not yet have been awarded a doctoral degree.

Experienced Researchers must, at the time of recruitment by the host organisation, be in possession of a doctoral degree or have at least four years of full-time equivalent research experience. In ITN, experienced researchers must also, at the time of recruitment by the host organisation, have less than five years of full-time equivalent research experience.

Full-Time Equivalent Research Experience is measured from the date when a researcher obtained the degree which would formally entitle him or her to embark on a doctorate, either in the country in which the degree was obtained or in the country in which the researcher is recruited or seconded, irrespective of whether or not a doctorate is or was ever envisaged.

Mobility: Researchers can be of any nationality. They are required to undertake trans-national mobility (i.e. move from one country to another) when taking up their appointment. One general rule applies to the appointment of researchers: At the time of recruitment by the host organisation, researchers must not have resided or carried out their main activity (work, studies, etc) in the country of their host organisation for more than 12 months in the 3 years immediately prior to the reference date. Short stays such as holidays and/or compulsory national service are not taken into account.