Within the ctDNA+ pts, additional survival benefit was derived for PD-L1-high pts (HR=0.52 [95% CI 0.331-0.82]; p=0.004), and TMB-high pts (HR=0.34 [95% CI 0.19-0.6]; p<0.0001])….Post-surgical ctDNA positivity, associated with high risk for recurrence and death, identified MIUC patients likely to benefit from adjuvant atezo.