The effect of poly(oxyethylene) on the L(2) phase of an anionic and a nonionic microemulsion system is studied. Attractive interactions between anionic surfactant and the polymer lead to polymer adsorption at the interface. The resulting increase of the surfactant monolayers’ elastic bending modulus of up to about 10% results in a shift of temperature-induced droplet cluster formation. For nonionic systems only sterical considerations are important due to repulsive interactions between the polymer and the surfactant.