X0102 24F-2NT LIVE 63075 XXXXXXXX false N-1A MFS Series Trust IX 111 Huntington Avenue Boston MA X1 02199 MFS INFLATION-ADJUSTED BOND FUND S000002493 R6 C000126364 A C000006724 R4 C000006725 B C000006726 C C000006727 I C000006728 R1 C000006730 R2 C000006732 R3 C000006733 811-2464 002-50409 10/31/2024 false false 150705159.00 119361586.00 0.00 119361586.00 31343573.00 0.00 0.0001531 4798.70 0 4798.70 David L. DiLorenzo David L. DiLorenzo President 01/21/2025