Following a request from the EU Commission, the Panel on Plant Health has addressed the pest categorisation of non-EU isolates of potato virus M (PVM). The information currently available on geographical distribution, biology, epidemiology, potential entry pathways, potential additional impact compared to the current situation in the EU and availability of control measures of non-EU isolates of PVM has been evaluated with regard to the criteria to qualify as a potential Union quarantine pest. Because non-EU isolates of PVM are absent from the EU, they do not meet one of the requirements to be regulated as a regulated non-quarantine pest (RNQP) (presence in the EU); as a consequence, the Panel decided not to evaluate the other RNQP criteria for these isolates. Populations of PVM can be subdivided into two strains: the ordinary strain (PVM-O) is present in the EU, while the divergent strain (PVM-D) is absent from the EU or considered to have at most a limited distribution in the EU. Non-EU isolates of PVM-O are not expected to have an additional impact in the EU compared to EU isolates and therefore do not meet the corresponding criterion to qualify as a potential Union quarantine pest. The Panel is unable to conclude on the potential impact of non-EU PVM-D isolates in the EU territory, but PVM-D isolates meet all the other criteria to qualify as a potential Union quarantine pest.