The present study is concerned with the reflection and propagation of thermoelastic plane waves from the stressâfree and thermally insulated surface of a homogeneous, isotropic thermally conducting elastic halfâspace in the frame of modified GreenâLindsay theory of generalized thermoelasticity with twoâtemperature (2TMGL). The thermoelastic coupling effect creates two types of coupled longitudinal waves which are dispersive as well as exhibit attenuation. Different from the thermoelastic coupling effect, there also exists one independent vertically shearâtype (SVâtype) wave. In contrast to the classical GreenâLindsay (GL) and LordâShulman (LS) theories of generalized thermoelasticity, the SVâtype wave is not only dispersive in nature but also experiences attenuation. Analytical expressions for the amplitude ratios and their respective energy ratios for reflected thermoelastic waves are determined when a coupled longitudinal wave is made incident on the free surface. The paper concludes with the numerical results on the phase speeds, amplitude ratios and their respective energy ratios for specific parameter choices. Various graphs have been plotted to analyze the behavior of these quantities. The characteristics of employing the 2TMGL model are discussed by comparing the numerical results obtained for the present model with those obtained in case of the twoâtemperature GreenâLindsay (2TGL) and twoâtemperature LordâShulman (2TLS)Â models.