X0201 N-CEN LIVE 0000063075 XXXXXXXX 811-02464 false false false N-1A S000002493 C000006732 C000006725 C000006724 C000006728 C000126364 C000006730 C000006726 C000006727 C000006733 MFS SERIES TRUST IX 811-02464 0000063075 549300IJONSVWD5I9F62 111 HUNTINGTON AVENUE 24TH FLOOR BOSTON 02199 US-MA US 617-954-5000 TerraNua Limited (New York, NY, US, Branch) 535 5th Avenue New York 10017 866-951-2280 Personal Trading System Autonomy Americas LLC 90 Park Avenue New York 10016 44-122-344-8000 Storage Vendor Charles River Development 700 District Avenue Burlington 01803 781-238-0099 Investment related records MFS Service Center, Inc 100 Hancock Street Quincy 02171 617-954-5000 Transfer Agency Record JPMorgan Chase & Co. 277 Park Avenue New York 10172 1-212-270-6000 Custodian Record Institutional Shareholder Services Inc. 702 King Farm Boulevard Suite 400 Rockville 20850 301-556-0500 Proxy Voting Administrator The Depository Trust Company 55 Water Street New York 10041 212-855-1000 DTC MFS Fund Distributors, Inc. 111 Huntington Avenue Boston 02199 617-954-5000 Principal Underwriter Record Iron Mountain, Inc. 150 SE Second Street Suite 211 Miami 33131 800-899-4766 Storage Vendor Massachusetts Financial Services Company 111 Huntington Avenue Boston 02199-7632 617-954-5000 Investment Adviser Record Ropes & Gray LLP 800 Boylston Street Boston 02199-3600 617-951-7000 Counsel Record State Street Bank and Trust Company 1 Lincoln Street Boston 02111 617-786-3000 Custody and Accounting Records DST Systems, Inc. 333 West 11th Street Kansas City 64105-1628 816-435-8655 Technology Vendor N N N-1A 5 Y Michael Hegarty 000000000 N John P. Kavanaugh 000000000 N Robert J. Manning 004646484 Y Laurie J. Thomsen 000000000 N Robin A. Stelmach 000000000 Y Steven E. Buller 000000000 N Maureen R. Goldfarb 000000000 N James W. Kilman, Jr. 000000000 N Maryanne L. Roepke 000000000 N John A. Caroselli 000000000 N Peter D. Jones 000000000 N Clarence Otis, Jr. 000000000 N Martin J. Wolin 004331075 111 Huntington Avenue Boston 02199 XXXXXX N N N N N N MFS Fund Distributors, Inc. 8-45321 000031052 0000000000 Y N Deloitte & Touche LLP 34 00000000000000000000 N N N N N N N MFS Inflation-Adjusted Bond Fund S000002493 VOHO802M9IKG3IZTEN75 N 9 0 0 N/A N N N N N/A N/A N/A Rule 22d-1 (17 CFR 270.22d-1) Rule 12d1-1 (17 CFR 270.12d1-1) Rule 32a-4 (17 CFR 270.32a-4) Y Y N N Massachusetts Financial Services Company 801-17352 000110045 1G3OSH3GLGJ7X1JC5I61 N MFS Service Center, Inc 84-1316 0000000000 Y N N ICE Data Services, Inc. 13-3668779 Tax ID N Refinitiv US Holdings Inc. 549300NF240HXJO7N016 N N Skandinaviska Enskilda Banken A/S F3JS33DEI6XQ4ZBPTN86 DK N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) FirstRand Bank Limited ZAYQDKTCATIXF9OQY690 ZA N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) State Street Trust Company Canada 549300L71XG2CTQ2V827 CA N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) State Street Bank and Trust Company 571474TGEMMWANRLN572 N N Bank - section 17(f)(1) (15 U.S.C. 80a-17(f)(1)) State Street Bank International GmbH ZMHGNT7ZPKZ3UFZ8EO46 DE N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Skandinaviska Enskilda Banken AB F3JS33DEI6XQ4ZBPTN86 SE N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) The Hongkong and Shanghai Banking Corporation Limited (Auckland, Auckland, NZ, Branch) 2HI3YI5320L3RW6NJ957 NZ N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Deutsche Bank Societa per Azioni 529900SS7ZWCX82U3W60 IT N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Skandinaviska Enskilda Banken AB (Helsinki, Uusimaa, FI, Branch) F3JS33DEI6XQ4ZBPTN86 FI N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Bank Hapoalim B.M. B6ARUI4946ST4S7WOU88 IL N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Deutsche Bank Aktiengesellschaft (Amsterdam, Noord Holland, NL, Branch) 7LTWFZYICNSX8D621K86 NL N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) UniCredit Bank Austria AG D1HEB8VEU6D9M8ZUXG17 AT N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Banco Nacional de Mexico, S.A., Integrante del Grupo Financiero Banamex 2SFFM4FUIE05S37WFU55 MX N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) The Hongkong and Shanghai Banking Corporation Limited (Sydney, NSW, AU, Branch) 2HI3YI5320L3RW6NJ957 AU N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) BNP Paribas Securities Services (Athens, Attica, GR, Branch) 549300WCGB70D06XZS54 GR N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Skandinaviska Enskilda Banken AB (Oslo, Oslo, NO, Branch) F3JS33DEI6XQ4ZBPTN86 NO N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Euroclear Bank 549300OZ46BRLZ8Y6F65 BE N Y Foreign securities depository - rule 17f-7 (17 CFR 270.17f-7) Credit Suisse (Schweiz) AG 549300CWR0W0BCS9Q144 CH N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) State Street Bank and Trust Company (Edinburgh, GB, Branch) 571474TGEMMWANRLN572 GB N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) Deutsche Bank Aktiengesellschaft (Madrid, Madrid, ES, Branch) 7LTWFZYICNSX8D621K86 ES N Y Foreign custodian - rule 17f-5 (17 CFR 270.17f-5) N MFS Service Center, Inc 0000000000 Y N N Massachusetts Financial Services Company 1G3OSH3GLGJ7X1JC5I61 Y N N 0 Nomura Securities International, Inc. 8-15255 000004297 OXTKY6Q8X53C9ILVV871 79581880.53 Barclays Capital Inc. 8-41342 000019714 AC28XWWI3WIBK2824319 260911012.4 UBS Securities LLC 8-22651 000007654 T6FIZBDPKLYJKFCRVK44 95518008.75 Natwest Markets Securities Inc. 8-37135 000011707 ZE2ZWJ5BTIQJ8M0C6K34 43372023.04 Morgan Stanley & Co. LLC 8-15869 000008209 9R7GPTSO7KV3UQJZQ078 42198516.82 BNP Paribas Securities Corp. 8-32682 000015794 RCNB6OTYUAMMP879YW96 20595258.48 Citigroup Global Markets Inc. 8-8177 000007059 MBNUM2BPBDO7JBLYG310 121898292.1 J.P. Morgan Securities LLC 8-35008 000000079 ZBUT11V806EZRVTWT807 98155969.45 BofA Securities, Inc. 8-69787 000283942 549300HN4UKV1E2R3U73 102231167.4 Goldman Sachs & Co. LLC 8-129 000000361 FOR8UP27PHTHYVLBNG30 37029793.31 988587803.86 N 1175054812.93 Uncommitted 100000000 N Uncommitted 200000000 N Committed 1250000000 N N N N true