The expert panel is comprised of 29 participants from seven European countries, the USA and Taiwan. To ensure heterogenicity, participants were selected from various fields of expertise: medical microbiology (PEV, KL, CL-F, TRR), infectious diseases (BJAR, MB, TC, CJC, OAC, DRG, NAFJ, BJK, OL, MH-N, TFP, FLvdV), intensive care medicine (EA, SB, PD, PW-LL, IM-L, JAS, LV, JW), clinical pharmacology (RJMB, RL, IS), public health (TC) and hematology (OAC, JM). Selected participants furthermore had specific expertise in epidemiology, diagnosis and management of invasive fungal diseases or fungal disease guideline development. The meeting was prepared by PEV, RJMB, JW and FLvdV. Case definitions were developed through a process of informal consensus. Although a systematic literature review was not performed, experts in the field presented overviews regarding epidemiology, pathogenesis, diagnosis and treatment of IAPA, which were followed by a group discussion process designed to allow members of the group to voice their opinions and contribute equally to the decision-making [12]. The goal of the consensus process was to bring the group to general agreement. Presentations and initial discussions took place on a single day meeting in April 2019 in Amsterdam and were continued through electronic exchange of views until consensus was achieved. The chosen framework included host and risk factors, clinical factors and mycological evidence, similar to the framework in the EORTC/MSGERC definitions and the AspICU algorithm [10, 11]. A medical writer made notes of the meeting, which were used as input to write the manuscript. A first draft manuscript was prepared by PEV, BJAR, RJMB, JW and FLvdV and circulated for comments from all experts. The experts reviewed and commented on the manuscript. Using these comments, a final version was circulated for approval. The logistics of the meeting were handled by a certified Congress organizer (Congress Care, s’Hertogenbosch, the Netherlands) with financial support of Pfizer (Pfizer B.V., Capelle aan den IJssel, the Netherlands). Congress Care and Pfizer had no influence on the selection of participants, selected topics, discussions, preparation and final approval of the content of the manuscript.