T-cells recognize MHC-embedded antigenic peptide fragments (pMHCs) on antigen presenting cells (APCs) through their clonotypic T-cell antigen receptors (TCRs), which typically feature only moderate affinities towards their pMHC ligands. Higher order TCR-structures, either constitutively present or dynamically formed upon pMHC binding, have thus long been considered instrumental for intracellular T-cell signaling and for maintaining high antigen sensitivity. Here we have determined the stoichiometry of the TCR and their non-covalently associated CD3 signaling chains in living antigen-experienced T-cells with the use of (i) single molecule Fluorescence Recovery After Photobleaching, (ii) Förster Resonance Energy Transfer (FRET) and (iii) photon arrival time - based fluorescence correlation spectroscopy (FCS) measurements. Using these approaches, we find exclusively monomeric TCR entities prior to and during pMHC binding. Hence, molecular events other than TCR clustering drive the recognition pMHCs at both high and low densities.