The guidance provides a new methodology for distinguishing between safe and potentially harmful strains of E. faecium in animal nutrition. It is intended for use by feed additive producers submitting applications to EFSA for safety assessment. Enterococci are well-known bacteria and are found in abundance in the gastrointestinal tract of both animals and humans. They are often used in the production of feed additives as a probiotic to prevent diarrhoea or to improve growth in animals.  The efficacy of the feed additives is assessed by EFSA’s experts together with their safety. Over the last 20 years, certain antibiotic-resistant, infectious strains of enterococci, including E.faecium, have been identified in hospital patients. Outside healthcare settings, enterococci very rarely present a risk of infection for humans. The development of new scientific approaches, particularly in the area of genomics, has allowed a far better understanding of why some strains of E. faecium present public health problems. Until now, for E. faecium-based additives to be deemed safe by EFSA, feed additive producers needed to demonstrate the absence of a number of genetic markers associated with the virulence of these bacteria. In this new EFSA guidance document, a practical methodology is given to differentiate between safe strains and the potentially harmful clinical strains of E. faecium, based on the bacteria’s susceptibility to the antibiotic ampicillin and the absence of three genetic markers associated with virulence. In practice, this will mean a significant reduction in the number of tests and data that producers must submit to EFSA as part of their applications for the authorisation of E. faecium-basedfeed additives. It also increases clarity for applicants in terms of the criteria EFSA uses to assess the safety of their products. The guidance document was developed over the last year by EFSA’s Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) in co-operation with the leading international experts in this area and was subject to a public consultation on EFSA´s website.