Currently, support tools are lacking to prioritize steps in the care coordination process to enable safe practice and effective clinical pathways in the first phase of acute psychiatric admissions. This study describes the development, validity, and reliability of an acute care coordination support tool, the Admission Team Score List (ATSL). The ATSL assists in care provider allocation during admissions. Face validity and feasibility of the ATSL were tested in 77 acute admissions. Endscores of filled out ATSL's were translated to recommended team compositions. These ATSL team (ATSL-T) compositions were compared to the actually present team (AP-T) and the most preferred team (MP-T) composition in hindsight. Consistency between the ATSL-T and the MP-T was substantial; Kw = 0.70, P < 0.001, 95% CI [0.55-0.84]. The consistency between the ATSL-T and AP-T was moderate; Kw = 0.43, P < 0.001, 95% CI [0.23-0.62]. The ATSL has an adequate (inter-rater) reliability; ICC = 0.90, P < 0.001, 95% CI [0.65-0.91]. The ATSL study is an important step to promote safety and efficient care based on care provider allocation, for service users experiencing an acute admission. The ATSL may stimulate structured clinical decision-making during the hectic process around acute psychiatric admissions.