Annual medics (Medicago spp.) have potential to increase forage production in the Southern Great Plains. Proper inoculation of seeds can result in more early-season forage. The objective of this study was to determine the optimal Rhizobia strains to maximize forage yield. Seven medic species (M. orbicularis, M. polymorpha, M. minima, M. rigidula, M. rigiduloides, M. arabica, and M. lupulina,), and six Rhizobia strains (M2, M49, WSM1115, Nitragin N, Nitragin alfalfa and clover, and BeckerUnderwood alfalfa) including a control were utilized. In the field of two years study, there was no difference in yields or nodule counts between inoculants at 110, 150, and 200 days after emergence for all species. The highest yield (4848 kg ha-1) was obtained from M. rigidula, and this was followed by M. polymorpha, M. rigiduloides, M. lupulina, M. minima, and M. orbicularis. Little nodulation was only observed for M. rigiduloides, M. orbicularis, and M. polymorpha. However, greenhouse study yielded different scenarios for each species. Based on plant vigor, nodule color and number, and dry weight of shoot and root, it appears that M49 is the only and best strain for M. rigiduloides; only Nitragin alfalfa and clover is moderately effective for M. rigidula; Nitragin N, WSM1115, and M2 are effective for M. arabica; Nitragin N, WSM1115, and M2 are very effective for M. orbicularis and M. polymorpha, and M49 is moderately effective for M. polymorpha; while Nitragin N, WSM1115, M2, and Nitragin alfalfa and clover are moderately to very effective for M. minima and M. lupulina. It is worth mentioning that some of the bacterial inoculants can produce nodules but they are not effective in fixing N with the indication of white color. Overall, the study summarized that the medics should be inoculated with species specific bacterial inoculants for effective nodulation and optimal forage yield.