X0101 24F-2NT LIVE 63075 XXXXXXXX false N-1A MFS Series Trust IX 111 Huntington Avenue Boston MA X1 02199 MFS CORPORATE BOND FUND S000002492 A C000006711 R4 C000006712 B C000006716 C C000006717 I C000006718 R1 C000006720 R2 C000006722 R3 C000006723 R6 C000070424 MFS LIMITED MATURITY FUND S000002495 I C000006744 A C000006745 R4 C000006746 B C000006750 C C000006751 R1 C000006753 R2 C000006755 R3 C000006756 R6 C000119776 MFS MUNICIPAL LIMITED MATURITY FUND S000002496 A C000006757 B C000006758 C C000006759 I C000092113 R6 C000195152 MFS TOTAL RETURN BOND FUND S000002497 A C000006760 R4 C000006761 B C000006765 C C000006766 I C000006767 R1 C000006769 R2 C000006771 R3 C000006772 R6 C000034443 811-2464 002-50409 04/30/2023 false false 6316183694.00 7378470068.00 0.00 7378470068.00 0.00 (1062286374.00) 0.0001102 0.00 0 0.00 David L. DiLorenzo David L. DiLorenzo President 07/18/2023