As macuser_22 said, code BG reports a rollover to a designated Roth account in a different qualified retirement plan like a 401(k), not to a Roth IRA. If the rollover was actually to a Roth IRA, the code should be H (without code B; code H is not permitted to be combined with code B since code H by itself already says that the distribution if from a designated Roth account in a qualified retirement plan).
