Per the IRS 1099R instructions:
G—Direct rollover and direct payment. Use Code G for a direct rollover from a qualified plan, a section 403(b) plan, or a governmental section 457(b) plan to an eligible retirement plan (another qualified plan, a section 403(b) plan, a governmental section 457(b) plan, or an IRA). See Direct Rollovers, earlier. Also, use Code G for a direct payment from an IRA to an accepting employer plan, and for IRRs that are direct rollovers. Note. Do not use Code G for a direct rollover from a designated Roth account to a Roth IRA. Use Code H.