Background: Adrenocortical Carcinoma (ACC) is a rare and aggressive malignancy with poor prognosis and limited treatments in the advanced setting. Molecular pathways with tumor suppressor genes (e.g. TP53, CDKN2A) and oncogenes (e.g. CTNNB1 and RAS) are implicated in oncogenesis. To our knowledge, the genomic landscape of ctDNA alterations for ACC has not been described in a large cohort. We report plasma-based ctDNA alterations in patients with advanced ACC. Methods: We retrospectively evaluated genomic data from 102 patients with ACC who had ctDNA testing between 12/2016 – 10/2020 using Guardant360 (Guardant Health, CA). ctDNA analysis interrogated single nucleotide variants (SNV), fusions, indels and copy number variations (CNV) of up to 83 genes. We evaluated the frequency of genomic alterations, the landscape of co-occurring mutations, and pathogenic or likely pathogenic alterations with potential targeted therapies. The prevalence of alterations identified in ctDNA were compared to those detected in tissue using a publicly available database (cBioPortal). Results: The median age was 54 years (range 24-81), and 55% of patients were male. Among the entire cohort, 84 pts (82.4%) had ≥1 somatic alteration detected. Mutations were most frequently detected in TP53 (52%), EGFR (23%), CTNNB1 (18%), MET (18%), and ATM (14%). The frequencies detected in ctDNA were similar to the results detected in tissue. Pathogenic and/or likely pathogenic mutations in therapeutically relevant alterations were observed in 36 patients (35%), including EGFR, BRAF, MET, CDKN2A, and CDK4/6 (Table 1). The most frequently co-occurring mutations were EGFR + TP53 (14%), EGFR + MET (11%), BRAF + MET (10%). Conclusions: Blood-based ctDNA profiling in advanced ACC provided comprehensive genomic data in most patients, with a similar profile to tumor tissue analyses. Over one third of patients had actionable mutations with approved therapies in other cancers. This approach might inform the development of personalized treatment options for this aggressive malignancy.