According to the conditions of the ERC Starting Grant 2017 call, a medical doctor degree (or applicants holding a degree in medicine) will not be accepted by itself as equivalent to a PhD award. To be considered an eligible Principal Investigator, medical doctors (or applicants holding a degree in medicine) need to provide the certificates of both a medical doctor degree and a PhD or proof of an appointment that requires doctoral equivalency (e.g. post-doctoral fellowship, professorship appointment). Additionally, candidates must also provide information on their research experience (including peer reviewed publications) in order to further substantiate the equivalence of their overall training to a PhD. In these cases, the certified date of the medical doctor degree completion plus two years is the time reference for calculation of the eligibility time-window (i.e. 4-9 years past the medical doctor degree for Starters).
For more information, see section 'Eligibility criteria' of the ERC Work Programme 2017