N-MFP2 0000798244 XXXXXXXX 2020-01-31 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 24 24 41268883.51 43741901.73 54797740.36 36232975.12 37637952.22 202060980.46 200681744.51 192641422.70 191933111.89 184049873.74 0.2040 0.2177 0.2738 0.1816 0.1879 0.9988 0.9988 0.9625 0.9619 0.9186 874.01 199554310.51 199542531.38 816061.66 310496.64 200048970.41 200278977.5570 1.0000 0.0154 0.9989 0.9989 0.9988 0.9988 0.9989 C000002179 1000.00 94088627.90 94197615.0070 0.9989 0.9989 0.9988 0.9988 0.9989 245184.22 499821.98 445031.87 1387477.50 684582.24 844760.93 557071.12 538705.85 474572.16 761896.90 2274153.30 3678399.27 0.0082 Y For Class A during the period, MFS waived: $825 management fees; MFD waived: $20,029 12b-1 fees. C000002180 250.00 214120.51 214367.7820 0.9989 0.9989 0.9989 0.9988 0.9989 165.64 301.00 0.00 0.00 0.00 2005.89 10.16 18164.78 0.00 0.00 175.80 20171.68 0.0077 Y For Class 529B during the period, MFS waived: $2 management fees; MFD waived: $192 12b-1 fees. C000002181 250.00 6406603.23 6414053.8280 0.9989 0.9989 0.9988 0.9988 0.9989 127007.59 145169.61 177856.95 184641.53 43258.09 195680.39 150449.93 89748.33 93646.50 138788.63 573597.56 639322.19 0.0077 Y For Class 529C during the period, MFS waived: $57 management fees; MFD waived: $5,485 12b-1 fees. C000002182 1000.00 8141695.64 8151121.5460 0.9989 0.9989 0.9989 0.9988 0.9989 229475.26 79693.43 40857.25 76564.92 11813.18 151946.21 18668.22 134370.48 82605.61 103150.48 160234.53 541520.05 0.0082 Y For Class B during the period, MFS waived: $73 management fees; MFD waived: $7,050 12b-1 fees. C000002183 1000.00 16173464.39 16192200.8020 0.9988 0.9988 0.9988 0.9988 0.9989 50273.44 47416.83 106841.38 138261.36 214868.21 254064.72 52235.70 524213.28 218273.19 269367.64 614307.11 1209958.83 0.0082 Y For Class C during the period, MFS waived: $145 management fees; MFD waived: $14,036 12b-1 fees. C000002184 1.00 7560983.31 7569687.6350 0.9989 0.9989 0.9989 0.9988 0.9989 89175.32 10874.69 139002.97 127429.91 20798.66 15.55 55387.98 217.98 23584.65 0.00 325581.11 127671.98 0.0081 Y For Class R1 during the period, MFS waived: $65 management fees; MFD waived: $6,336 12b-1 fees. C000002186 1.00 28742433.08 28774931.1510 0.9989 0.9989 0.9988 0.9988 0.9989 250869.09 273572.65 220112.06 321835.02 16150.16 169745.05 225421.69 1851.06 823496.09 222344.40 1307013.38 989348.18 0.0082 Y For Class R2 during the period, MFS waived: $245 management fees; MFD waived: $11,881 12b-1 fees. C000002187 1.00 14871411.85 14888587.4390 0.9989 0.9989 0.9989 0.9988 0.9989 32810.02 126434.43 131026.63 154853.34 12781.91 88494.69 5066.14 131096.27 167835.81 169397.79 328423.56 670170.43 0.0082 Y For Class R3 during the period, MFS waived: $131 management fees; MFD waived: $3,178 12b-1 fees. C000002188 1.00 2718168.90 2721308.5710 0.9989 0.9989 0.9989 0.9988 0.9989 2220.01 6.60 0.00 0.00 0.00 0.00 465.30 0.00 0.00 590.32 2503.52 596.92 0.0082 Y For Class R4 during the period, MFS waived: $24 management fees. C000002189 250.00 20173847.29 20197058.0760 0.9989 0.9989 0.9988 0.9988 0.9989 475279.01 240261.25 384075.94 1000506.05 318789.45 319897.73 175872.90 434100.43 247135.68 172363.32 1411710.49 2026413.81 0.0077 Y For Class 529A during the period, MFS waived: $177 management fees; MFD waived: $4,326 12b-1 fees. C000206004 1.00 119066.94 119204.4300 0.9995 0.9995 0.9995 0.9988 0.9989 64529.39 0.00 63.69 3.80 15.74 0.00 0.00 144.64 8.02 0.00 64548.93 80.53 0.0089 Y For Class R6 during the period, MFS waived: $1 management fees. C000206005 1.00 838547.37 838841.2900 0.9989 0.9997 0.9997 0.9988 0.9997 44.70 1.04 195328.17 1.04 0.00 0.00 0.00 227.32 779355.60 195327.13 974501.15 195329.21 0.0079 Y For Class I during the period, MFS waived: $3 management fees. BOFA Securities Bank of America NA 1.570000% 549300HN4UKV1E2R3U73 0001102113 03199T002_1.57_0203 U.S. Treasury Repurchase Agreement, if collateralized only by U.S. Treasuries (including Strips) and cash Y N U.S. Treasury Bill 254900HROIFWPRGM1V77 2023-03-31 1.500000 3380000.00 3414763.93 U.S. Treasuries (including strips) Y 2020-02-03 2020-02-03 2020-02-03 N N N 0.0157 3331000.00 3331000.00 0.0167 N Y Y N Federal Farm Credit Bank Federal Farm Credit Banks 313312TA8 US313312TA80 U.S. Government Agency Debt Y 2020-02-13 2020-02-13 2020-02-13 N N N 0.0157 5247739.56 5247739.56 0.0262 N N Y N Federal Farm Credit Bank Federal Farm Credit Banks 313312TG5 US313312TG50 U.S. Government Agency Debt Y 2020-02-19 2020-02-19 2020-02-19 N N N 0.0157 11756895.21 11756895.21 0.0588 N N Y N Federal Farm Credit Bank Federal Farm Credit Banks 313312TN0 US313312TN02 U.S. Government Agency Debt Y 2020-02-25 2020-02-25 2020-02-25 N N N 0.0157 14326416.87 14326416.87 0.0716 N N Y N Federal Farm Credit Bank Federal Farm Credit Banks 313312TX8 US313312TX83 U.S. Government Agency Debt Y 2020-03-05 2020-03-05 2020-03-05 N N N 0.0158 8688313.03 8688313.03 0.0434 N N Y N Federal Home Loan Bank Federal Home Loan Bank 313384SR1 2549001DPIFGXC1TOL40 US313384SR10 U.S. Government Agency Debt Y 2020-02-04 2020-02-04 2020-02-04 N N N 0.0158 5938744.27 5938744.27 0.0297 N N Y N Federal Home Loan Bank Federal Home Loan Bank 313384SX8 2549001DPIFGXC1TOL40 US313384SX87 U.S. Government Agency Debt Y 2020-02-10 2020-02-10 2020-02-10 N N N 0.0157 8032578.33 8032578.33 0.0402 N N Y N Federal Home Loan Bank Federal Home Loan Bank 313384SZ3 2549001DPIFGXC1TOL40 US313384SZ36 U.S. Government Agency Debt Y 2020-02-12 2020-02-12 2020-02-12 N N N 0.0157 8296783.75 8296783.75 0.0415 N N Y N Federal Home Loan Bank Federal Home Loan Bank 313384TG4 2549001DPIFGXC1TOL40 US313384TG46 U.S. Government Agency Debt Y 2020-02-19 2020-02-19 2020-02-19 N N N 0.0157 9611374.26 9611374.26 0.0480 N N Y N Federal Home Loan Bank Federal Home Loan Bank 313384VH9 2549001DPIFGXC1TOL40 US313384VH90 U.S. Government Agency Debt Y 2020-04-08 2020-04-08 2020-04-08 N N N 0.0160 7997265.55 7997265.55 0.0400 N N N N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396TH6 S6XOOCT0IEG5ABCC6L87 US313396TH66 U.S. Government Agency Debt Y 2020-02-20 2020-02-20 2020-02-20 N N N 0.0157 10192534.22 10192534.22 0.0510 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396TN3 S6XOOCT0IEG5ABCC6L87 US313396TN35 U.S. Government Agency Debt Y 2020-02-25 2020-02-25 2020-02-25 N N N 0.0157 9391096.13 9391096.13 0.0469 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396TP8 S6XOOCT0IEG5ABCC6L87 US313396TP82 U.S. Government Agency Debt Y 2020-02-26 2020-02-26 2020-02-26 N N N 0.0157 15050081.43 15050081.43 0.0752 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396VH3 S6XOOCT0IEG5ABCC6L87 US313396VH39 U.S. Government Agency Debt Y 2020-04-08 2020-04-08 2020-04-08 N N N 0.0160 7496688.58 7496688.58 0.0375 N N N N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588TA3 B1V7KEBTPIMZEU4LTD58 US313588TA38 U.S. Government Agency Debt Y 2020-02-13 2020-02-13 2020-02-13 N N N 0.0157 8096512.46 8096512.46 0.0405 N N Y N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588TB1 B1V7KEBTPIMZEU4LTD58 US313588TB11 U.S. Government Agency Debt Y 2020-02-14 2020-02-14 2020-02-14 N N N 0.0157 10994790.29 10994790.29 0.0550 N N Y N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588TF2 B1V7KEBTPIMZEU4LTD58 US313588TF25 U.S. Government Agency Debt Y 2020-02-18 2020-02-18 2020-02-18 N N N 0.0157 7994833.36 7994833.36 0.0400 N N Y N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588TJ4 B1V7KEBTPIMZEU4LTD58 US313588TJ47 U.S. Government Agency Debt Y 2020-02-21 2020-02-21 2020-02-21 N N N 0.0157 5635629.00 5635629.00 0.0282 N N Y N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588UF0 B1V7KEBTPIMZEU4LTD58 US313588UF06 U.S. Government Agency Debt Y 2020-03-13 2020-03-13 2020-03-13 N N N 0.0158 7167865.80 7167865.80 0.0358 N N Y N Goldman Sachs & Co. LLC Goldman Sachs & Co. LLC 1.570000% FOR8UP27PHTHYVLBNG30 0000769993 318991007_1.57_0203 U.S. Treasury Repurchase Agreement, if collateralized only by U.S. Treasuries (including Strips) and cash Y N U.S. Treasury Bill 254900HROIFWPRGM1V77 2044-02-15 1.375000 7840800.00 10872913.04 U.S. Treasuries (including strips) U.S. Treasury Bill 254900HROIFWPRGM1V77 2029-01-15 0.875000 1419600.00 1571126.29 U.S. Treasuries (including strips) Y 2020-02-03 2020-02-03 2020-02-03 N N N 0.0157 12200000.00 12200000.00 0.0610 N Y Y N U.S. Treasury Bill U.S. Treasury Bill 912796TK5 254900HROIFWPRGM1V77 US912796TK58 U.S. Treasury Debt Y 2020-03-12 2020-03-12 2020-03-12 N N N 0.0156 12120345.83 12120345.83 0.0606 N Y Y N U.S. Treasury Bill U.S. Treasury Bill 912796WS4 254900HROIFWPRGM1V77 US912796WS48 U.S. Treasury Debt Y 2020-02-11 2020-02-11 2020-02-11 N N N 0.0145 9986822.58 9986822.58 0.0499 N Y Y N MFS Series Trust I 2020-02-07 /s/Kino Clark Kino Clark Assistant Treasurer