Mobile genetic elements are major vehicles of antibiotic resistance genes. Integrative Mobilizable Elements (IMEs) are widespread but very poorly known elements that excise from the chromosome and transfer by conjugation by hijacking the conjugation machinery of a co-resident conjugative element. Previous work led to the identification of IMEs integrated inside ICEs of the Tn916/ICESt3 superfamily. Integration of the IME interrupts the origin of transfer (oriT), necessary for conjugative transfer of the ICE. In silico search enabled the identification of 53 IME_oriT in 13 different species of streptococci and in Staphylococcus aureus. IMEs were found integrated in three different families of Integrative Conjugative Elements but also in an IME and other less specific chromosomal sites. Half of them carry an lsa(C) gene conferring lincosamides-streptogramin A-pleuromutilin resistance. We tested the mobility of one of these IME_oriT. Since the IME is inserted inside an ICE, it could theoretically transfer either passively as a cargo element of the ICE or actively after excision and transfer using the conjugation machinery of the ICE. Conjugation experiments with different pairs of donor-recipient cells (wild-type or mutants interrupted in either integrase or relaxase gene) demonstrated that the tested IME_oriT can excise and transfer separately from the ICE. IME transfer occurs without interfering with the concomitant transfer of the ICE, indicating a commensal relationship between elements. This family of elements, more widespread than initially thought, can actively participate in the dissemination of resistance genes not only in streptococci but also to other Firmicutes.