N-MFP2 0000798244 XXXXXXXX 2019-10-31 0000798244 CQT3VZHUKW04X1YLM325 S000000762 12 N N 033-07638 Massachusetts Financial Services Company 801-17352 Deloitte & Touche LLP Boston MA Massachusetts Financial Services Company MFS Service Center, Inc 0000769188 084-01316 N N N Exempt Government N 33 33 44847238.63 38814348.62 54126797.48 49209741.62 188651789.62 210496544.08 209992421.39 202796606.36 0.00 0.2128 0.1844 0.2577 0.2343 0.8951 0.9998 0.9998 0.9656 0.0000 143.10 208779084.66 208760556.06 278519.21 348003.26 208691215.11 208921222.1560 1.0000 0.0184 0.9991 0.9990 0.9990 0.9990 0.0000 C000002179 1000.00 98414563.53 98523033.2930 0.9991 0.9990 0.9990 0.9990 0.0000 464271.23 624222.04 234400.50 286164.42 854149.11 815699.81 495700.11 355062.68 0.00 0.00 2320563.73 2327145.73 0.0115 Y For Class A during the period, MFS waived: $857 management fees; MFD waived: $20,814 12b-1 fees. C000002180 250.00 253782.49 254062.4340 0.9991 0.9990 0.9990 0.9990 0.0000 272.80 0.00 0.00 0.00 4646.39 2841.35 11417.19 16908.48 0.00 0.00 16336.38 19749.83 0.0109 Y For Class 529B during the period, MFS waived: $2 management fees; MFD waived: $218 12b-1 fees. C000002181 250.00 6668539.75 6675870.0590 0.9991 0.9991 0.9990 0.9990 0.0000 114724.37 20150.59 8290.98 26080.36 84175.47 14316.15 177069.12 104104.03 0.00 0.00 333758.04 171328.28 0.0110 Y For Class 529C during the period, MFS waived: $57 management fees; MFD waived: $5,557 12b-1 fees. C000002182 1000.00 8565138.36 8574601.8610 0.9991 0.9990 0.9990 0.9990 0.0000 16483.89 28683.19 0.00 117494.27 16146.49 59607.95 43445.61 144682.08 0.00 0.00 76274.83 370985.68 0.0115 Y For Class B during the period, MFS waived: $76 management fees; MFD waived: $7,367 12b-1 fees. C000002183 1000.00 19095545.94 19116679.2690 0.9991 0.9991 0.9990 0.9990 0.0000 497355.46 66752.96 39377.09 67116.25 64649.64 324454.05 44041.60 143847.48 0.00 0.00 702660.80 719601.59 0.0115 Y For Class C during the period, MFS waived: $169 management fees; MFD waived: $16,362 12b-1 fees. C000002184 1.00 7510813.87 7519065.1450 0.9991 0.9990 0.9990 0.9990 0.0000 21114.25 0.00 9496.47 19559.50 14950.15 913.49 5659.38 34722.63 0.00 0.00 80583.77 61332.38 0.0115 Y For Class R1 during the period, MFS waived: $65 management fees; MFD waived: $6,352 12b-1 fees. C000002186 1.00 29610499.62 29642973.5710 0.9991 0.9990 0.9990 0.9990 0.0000 45573.86 289607.30 18871.68 394423.83 23863.11 291516.44 54739.11 1349321.74 0.00 0.00 375783.21 2394103.86 0.0115 Y For Class R2 during the period, MFS waived: $267 management fees; MFD waived: $12,998 12b-1 fees. C000002187 1.00 15769512.88 15786937.0230 0.9991 0.9990 0.9990 0.9990 0.0000 36340.53 10220.74 97119.53 5055.11 11854.10 177001.41 319004.95 2910.83 0.00 0.00 466568.44 221310.66 0.0115 Y For Class R3 during the period, MFS waived: $136 management fees; MFD waived: $3,307 12b-1 fees. C000002188 1.00 2710378.31 2713368.1210 0.9991 0.9990 0.9990 0.9990 0.0000 3195.18 763.19 0.00 379.15 181.79 0.00 848.23 916.07 0.00 0.00 4225.20 1295.22 0.0115 Y For Class R4 during the period, MFS waived: $24 management fees. C000002189 250.00 19980303.01 20002370.3300 0.9991 0.9990 0.9990 0.9990 0.0000 159585.74 116122.38 112369.96 93017.24 159654.12 124067.79 217360.70 61528.27 0.00 0.00 680328.48 432007.53 0.0110 Y For Class 529A during the period, MFS waived: $173 management fees; MFD waived: $4,207 12b-1 fees. C000206004 1.00 54499.89 54560.0100 0.9991 0.9990 0.9990 0.9990 0.0000 64.17 0.00 0.00 3.79 0.00 0.00 0.00 0.55 0.00 0.00 64.17 4.34 0.0122 Y For Class R6 during the period, MFS waived: $1 management fees. C000206005 1.00 57637.46 57701.0400 0.9991 0.9990 0.9990 0.9990 0.0000 20554.61 19991.48 0.00 0.00 350.00 0.00 0.00 1.51 0.00 0.00 20904.61 19992.99 0.0115 Y For Class I during the period, MFS waived: $1 management fees. BOFA Securities BOFA Securities 1.730000% 549300HN4UKV1E2R3U73 0001102113 03199T002_1.73_1101 U.S. Treasury Repurchase Agreement, if collateralized only by U.S. Treasuries (including Strips) and cash Y N U.S. Treasury Bill 254900HROIFWPRGM1V77 2026-07-31 1.875000 5377000.00 5491519.93 U.S. Treasuries (including strips) Y 2019-11-01 2019-11-01 2019-11-01 N N N 0.0173 5383000.00 5383000.00 0.0258 N Y Y N Federal Farm Credit Bank Federal Farm Credit Bank 313312PE4 US313312PE49 U.S. Government Agency Debt Y 2019-11-13 2019-11-13 2019-11-13 N N N 0.0170 6556326.40 6556326.40 0.0314 N N Y N Federal Farm Credit Bank Federal Farm Credit Bank 313312QB9 US313312QB90 U.S. Government Agency Debt Y 2019-12-04 2019-12-04 2019-12-04 N N N 0.0170 11991614.73 11991614.73 0.0575 N N Y N Federal Farm Credit Bank Federal Farm Credit Bank 313312QC7 US313312QC73 U.S. Government Agency Debt Y 2019-12-05 2019-12-05 2019-12-05 N N N 0.0170 3993691.12 3993691.12 0.0191 N N Y N Federal Farm Credit Bank Federal Farm Credit Bank 313312SB7 US313312SB72 U.S. Government Agency Debt Y 2020-01-21 2020-01-21 2020-01-21 N N N 0.0165 14736090.45 14736090.45 0.0706 N N N N Federal Farm Credit Bank Federal Farm Credit Bank 313312SL5 US313312SL54 U.S. Government Agency Debt Y 2020-01-30 2020-01-30 2020-01-30 N N N 0.0159 4352301.50 4352301.50 0.0209 N N N N Federal Home Loan Bank Federal Home Loan Bank 313384NS4 2549001DPIFGXC1TOL40 US313384NS48 U.S. Government Agency Debt Y 2019-11-01 2019-11-01 2019-11-01 N N N 0.0001 9005000.00 9005000.00 0.0431 N Y Y N Federal Home Loan Bank Federal Home Loan Bank 313384PM5 2549001DPIFGXC1TOL40 US313384PM59 U.S. Government Agency Debt Y 2019-11-20 2019-11-20 2019-11-20 N N N 0.0170 16050755.65 16050755.65 0.0769 N N Y N Federal Home Loan Bank Federal Home Loan Bank 313384PN3 2549001DPIFGXC1TOL40 US313384PN33 U.S. Government Agency Debt Y 2019-11-21 2019-11-21 2019-11-21 N N N 0.0170 6314101.35 6314101.35 0.0303 N N Y N Federal Home Loan Bank Federal Home Loan Bank 313384PP8 2549001DPIFGXC1TOL40 US313384PP80 U.S. Government Agency Debt Y 2019-11-22 2019-11-22 2019-11-22 N N N 0.0171 10514685.50 10514685.50 0.0504 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396PE7 S6XOOCT0IEG5ABCC6L87 US313396PE71 U.S. Government Agency Debt Y 2019-11-13 2019-11-13 2019-11-13 N N N 0.0170 13411485.36 13411485.36 0.0643 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396PL1 S6XOOCT0IEG5ABCC6L87 US313396PL15 U.S. Government Agency Debt Y 2019-11-19 2019-11-19 2019-11-19 N N N 0.0170 6604447.60 6604447.60 0.0316 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396QA4 S6XOOCT0IEG5ABCC6L87 US313396QA41 U.S. Government Agency Debt Y 2019-12-03 2019-12-03 2019-12-03 N N N 0.0170 4393468.46 4393468.46 0.0211 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396QB2 S6XOOCT0IEG5ABCC6L87 US313396QB24 U.S. Government Agency Debt Y 2019-12-04 2019-12-04 2019-12-04 N N N 0.0170 2196632.17 2196632.17 0.0105 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396QC0 S6XOOCT0IEG5ABCC6L87 US313396QC07 U.S. Government Agency Debt Y 2019-12-05 2019-12-05 2019-12-05 N N N 0.0170 10563313.01 10563313.01 0.0506 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396QD8 S6XOOCT0IEG5ABCC6L87 US313396QD89 U.S. Government Agency Debt Y 2019-12-06 2019-12-06 2019-12-06 N N N 0.0170 5291394.87 5291394.87 0.0254 N N Y N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588PE9 B1V7KEBTPIMZEU4LTD58 US313588PE95 U.S. Government Agency Debt Y 2019-11-13 2019-11-13 2019-11-13 N N N 0.0170 19244217.20 19244217.20 0.0922 N N Y N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588PG4 B1V7KEBTPIMZEU4LTD58 US313588PG44 U.S. Government Agency Debt Y 2019-11-15 2019-11-15 2019-11-15 N N N 0.0170 7145328.69 7145328.69 0.0342 N N Y N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588PZ2 B1V7KEBTPIMZEU4LTD58 US313588PZ25 U.S. Government Agency Debt Y 2019-12-02 2019-12-02 2019-12-02 N N N 0.0170 8572654.25 8572654.25 0.0411 N N Y N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588RV9 B1V7KEBTPIMZEU4LTD58 US313588RV92 U.S. Government Agency Debt Y 2020-01-15 2020-01-15 2020-01-15 N N N 0.0165 6911594.38 6911594.38 0.0331 N N N N Goldman Sachs & Co. LLC Goldman Sachs & Co. LLC 1.660000% FOR8UP27PHTHYVLBNG30 0000769993 318991007_1.66_1101 U.S. Government Agency Repurchase Agreement, collateralized only by U.S. Government Agency securities, U.S. Treasuries, and cash Y N Federal Home Loan Bank 2549001DPIFGXC1TOL40 2036-07-15 5.500000 8485000.00 12241408.49 Agency Mortgage-Backed Securities Y 2019-11-01 2019-11-01 2019-11-01 N N N 0.0166 12000000.00 12000000.00 0.0575 N Y Y N U.S. Treasury Bill U.S. Treasury Bill 912796TA7 254900HROIFWPRGM1V77 US912796TA76 U.S. Treasury Debt Y 2020-01-09 2020-01-09 2020-01-09 N N N 0.0156 11585868.69 11585868.69 0.0555 N Y Y N U.S. Treasury Bill U.S. Treasury Bill 912796TB5 254900HROIFWPRGM1V77 US912796TB59 U.S. Treasury Debt Y 2020-01-16 2020-01-16 2020-01-16 N N N 0.0156 11961113.28 11961113.28 0.0573 N Y Y N MFS Series Trust I 2019-11-07 /s/Kino Clark Kino Clark Assistant Treasurer