The reaction between ground state atomic yttrium (a²D_J) and ethane (C₂H₆) has been studied in crossed molecular beams with 157 nm photoionization detection of products. Studies have been carried out at several collision energies, ranging from <E_coll> = 16.1 kcal/mol to <E_coll> = 29.8 kcal/mol. At <E_coll> ³ 18.1 kcal/mol, reactive scattering is observed, with both YH₂ + C₂H₄ and YC₂H₄ + H₂ products being formed. Detected products of the YH₂ + C₂H₄ channel are found to exhibit very little translational energy, suggesting that there is little or no barrier above the final product energy to ethylene elimination from an (H)₂Y(C₂H₄) intermediate. Translational energy distributions for the YC₂H₄ + H₂ channel, resulting from elimination of H₂ from a common intermediate, demonstrate that a slightly larger fraction of energy available to these products is channeled into translation. The YH₂ + C₂H₄ channel is found to dominate the H₂ elimination channel by greater than an order of magnitude, which suggests that a small barrier exists to the less endoergic H₂ elimination channel. In lower collision energy studies, only non-reactive scattering of Y atoms from ethane is found to occur. This observed collision energy threshold behavior for the onset of YH₂ and YC₂H₄ product formation allows determination of the barrier to C-H bond insertion of Y atoms into ethane to be 19.9 ± 3.0 kcal/mol.