This investigation sought to reveal the dynamic mechanism for self-exchange between an adsorbed homopolymer layer and chains in free solution, employing poly(ethylene oxide) (PEO) adsorbed on silica from aqueous solution as a model system. Fluorescence tracer studies of individual populations within a saturated adsorbed layer revealed no dynamic distinctions between those chains which reached the interface early or late during the initial layer preparation. This observation ruled out the explanation of trapped and mobile subpopulations for bimodally shaped self-exchange kinetic traces. Studies focusing on chains aged in unsaturated or starved layers revealed faster self-exchange rates compared with chains aged in saturated layers. Surface coverage was found to be more important than molecular weight in controlling the exchange rate. Taken together, these results ruled out the number and strength of segment-surface contacts per chains as the determining kinetic factor in exchange dynamics. Interactions between neighboring chains were shown to be extremely important; however, if classical melt-type entanglements played a role, they did so only at extremely high molecular weights, above 112K. The osmotic barrier posed by loops and tails of the existing layer (present only at moderate and high surfaces coverages) to approaching chains from solution was thought to provide a substantial kinetic barrier to the approach chains from solution.