N-MFP2 0000798244 XXXXXXXX 2019-02-28 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 28588495.13 40786001.89 42749385.73 39450721.44 182722505.96 209470453.33 202454234.64 220636307.34 0.00 0.1273 0.1777 0.1927 0.1720 0.8137 0.9125 0.9127 0.9617 0.0000 0.00 219156424.40 219161211.96 804167.00 432746.28 219532632.68 219762639.5100 1.0000 0.0240 0.9989 0.9989 0.9989 0.9989 0.0000 C000002179 1000.00 101184422.04 101290527.7920 0.9989 0.9989 0.9989 0.9989 0.0000 529647.89 3465637.38 537136.38 1900640.10 3171517.06 4050109.43 466305.49 827027.08 0.00 0.00 4961712.47 8915828.20 0.0169 Y For Class A during the period, MFS waived: $783 management fees; MFD waived: $19,693 12b-1 fees. C000002180 250.00 243566.40 243820.9440 0.9990 0.9990 0.9990 0.9989 0.0000 4638.62 3500.00 184.00 0.00 11300.90 0.00 381.65 3247.08 0.00 0.00 12198.05 3247.08 0.0164 Y For Class 529B during the period, MFS waived: $2 management fees; MFD waived: $185 12b-1 fees. C000002181 250.00 6865050.33 6872183.1720 0.9990 0.9990 0.9990 0.9989 0.0000 15101.02 65874.61 286771.79 6800.00 68871.58 31876.68 182979.85 104610.84 0.00 0.00 591160.39 148588.15 0.0164 Y For Class 529C during the period, MFS waived: $51 management fees; MFD waived: $5,144 12b-1 fees. C000002182 1000.00 10621784.80 10632957.6400 0.9990 0.9989 0.9989 0.9989 0.0000 66024.62 184585.79 2729.66 137465.04 158502.12 248280.67 16473.41 329640.71 0.00 0.00 284716.80 946929.00 0.0169 Y For Class B during the period, MFS waived: $84 management fees; MFD waived: $8,411 12b-1 fees. C000002183 1000.00 20181970.22 20203358.9580 0.9989 0.9990 0.9989 0.9989 0.0000 325496.15 852786.02 355786.40 231890.83 107359.12 864784.02 5396.21 468578.82 0.00 0.00 570710.67 2321950.32 0.0169 Y For Class C during the period, MFS waived: $161 management fees; MFD waived: $16,155 12b-1 fees. C000002184 1.00 8127998.75 8136731.0080 0.9990 0.9990 0.9990 0.9989 0.0000 69151.76 7576.51 9733.94 63240.31 14245.58 14275.76 10596.41 11794.68 0.00 0.00 56348.32 325532.28 0.0169 Y For Class R1 during the period, MFS waived: $64 management fees; MFD waived: $6,396 12b-1 fees. C000002186 1.00 34581880.47 34618030.7470 0.9990 0.9989 0.9989 0.9989 0.0000 195465.15 569265.57 37115.71 485300.87 317658.07 302758.24 3545.39 298623.56 0.00 0.00 464872.30 1139438.95 0.0169 Y For Class R2 during the period, MFS waived: $266 management fees; MFD waived: $13,378 12b-1 fees. C000002187 1.00 16788675.63 16806194.6040 0.9990 0.9990 0.9989 0.9989 0.0000 42209.24 40189.46 694133.92 853708.57 29830.20 207585.30 20077.74 38820.82 0.00 0.00 1162115.42 1492383.12 0.0169 Y For Class R3 during the period, MFS waived: $129 management fees; MFD waived: $3,249 12b-1 fees. C000002188 1.00 2748116.16 2750988.9440 0.9990 0.9990 0.9990 0.9989 0.0000 3882.26 0.00 221.99 0.00 0.00 0.00 873.61 0.00 0.00 0.00 4977.86 780.57 0.0169 Y For Class R4 during the period, MFS waived: $21 management fees. C000002189 250.00 18063713.52 18082260.2310 0.9990 0.9990 0.9990 0.9989 0.0000 599177.05 101641.63 149467.21 76906.06 803594.00 373208.13 301207.78 21948.50 0.00 0.00 2056875.98 509727.99 0.0164 Y For Class 529A during the period, MFS waived: $132 management fees; MFD waived: $3,332 12b-1 fees. C000206004 1.00 50247.09 50299.6000 0.9990 0.9990 0.9990 0.9989 0.0000 73.95 0.00 0.00 0.00 0.00 0.00 0.00 1.82 0.00 0.00 73.95 1.82 0.0176 N C000206005 1.00 75207.27 75285.8700 0.9990 0.9990 0.9993 0.9989 0.0000 71.13 0.00 0.00 0.00 25000.00 0.00 0.00 27.93 0.00 0.00 25071.13 27.93 0.0169 N Federal Farm Credit Bank Federal Farm Credit Bank 313312CQ1 US313312CQ16 U.S. Government Agency Debt Y 2019-03-04 2019-03-04 2019-03-04 N N N 0.0241 2499505.00 2499505.00 0.0114 N N Y N Federal Farm Credit Bank Federal Farm Credit Bank 313312CU2 US313312CU28 U.S. Government Agency Debt Y 2019-03-08 2019-03-08 2019-03-08 N N N 0.0241 10195277.40 10195277.40 0.0464 N N Y N Federal Farm Credit Bank Federal Farm Credit Bank 313312CX6 US313312CX66 U.S. Government Agency Debt Y 2019-03-11 2019-03-11 2019-03-11 N N N 0.0241 7095306.90 7095306.90 0.0323 N N Y N Federal Farm Credit Bank Federal Farm Credit Bank 313312DE7 US313312DE76 U.S. Government Agency Debt Y 2019-03-18 2019-03-18 2019-03-18 N N N 0.0242 4994380.00 4994380.00 0.0228 N N Y N Federal Farm Credit Bank Federal Farm Credit Bank 313312DF4 US313312DF42 U.S. Government Agency Debt Y 2019-03-19 2019-03-19 2019-03-19 N N N 0.0242 99881.00 99881.00 0.0005 N N Y N Federal Farm Credit Bank Federal Farm Credit Bank 313312DG2 US313312DG25 U.S. Government Agency Debt Y 2019-03-20 2019-03-20 2019-03-20 N N N 0.0242 5992464.00 5992464.00 0.0273 N N Y N Federal Farm Credit Bank Federal Farm Credit Bank 313312EC0 US313312EC02 U.S. Government Agency Debt Y 2019-04-09 2019-04-09 2019-04-09 N N N 0.0245 14362401.60 14362401.60 0.0654 N N Y N Federal Home Loan Bank Federal Home Loan Bank 313384CM9 2549001DPIFGXC1TOL40 US313384CM96 U.S. Government Agency Debt Y 2019-03-01 2019-03-01 2019-03-01 N N N 0.0001 4500000.00 4500000.00 0.0205 N Y Y N Federal Home Loan Bank Federal Home Loan Bank 313384CQ0 2549001DPIFGXC1TOL40 US313384CQ01 U.S. Government Agency Debt Y 2019-03-04 2019-03-04 2019-03-04 N N N 0.0241 5531904.47 5531904.47 0.0252 N N Y N Federal Home Loan Bank Federal Home Loan Bank 313384CZ0 2549001DPIFGXC1TOL40 US313384CZ00 U.S. Government Agency Debt Y 2019-03-13 2019-03-13 2019-03-13 N N N 0.0241 8992863.00 8992863.00 0.0410 N N Y N Federal Home Loan Bank Federal Home Loan Bank 313384DA4 2549001DPIFGXC1TOL40 US313384DA40 U.S. Government Agency Debt Y 2019-03-14 2019-03-14 2019-03-14 N N N 0.0242 2048239.05 2048239.05 0.0093 N N Y N Federal Home Loan Bank Federal Home Loan Bank 313384DH9 2549001DPIFGXC1TOL40 US313384DH92 U.S. Government Agency Debt Y 2019-03-21 2019-03-21 2019-03-21 N N N 0.0242 8888234.20 8888234.20 0.0405 N N Y N Federal Home Loan Bank Federal Home Loan Bank 313384EE5 2549001DPIFGXC1TOL40 US313384EE52 U.S. Government Agency Debt Y 2019-04-11 2019-04-11 2019-04-11 N N N 0.0245 6980785.00 6980785.00 0.0318 N N Y N Federal Home Loan Bank Federal Home Loan Bank 313384EF2 2549001DPIFGXC1TOL40 US313384EF28 U.S. Government Agency Debt Y 2019-04-12 2019-04-12 2019-04-12 N N N 0.0245 7977504.00 7977504.00 0.0363 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396CR2 S6XOOCT0IEG5ABCC6L87 US313396CR22 U.S. Government Agency Debt Y 2019-03-05 2019-03-05 2019-03-05 N N N 0.0241 7098125.60 7098125.60 0.0323 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396DW0 S6XOOCT0IEG5ABCC6L87 US313396DW08 U.S. Government Agency Debt Y 2019-04-03 2019-04-03 2019-04-03 N N N 0.0245 9179677.20 9179677.20 0.0418 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396DX8 S6XOOCT0IEG5ABCC6L87 US313396DX80 U.S. Government Agency Debt Y 2019-04-04 2019-04-04 2019-04-04 N N N 0.0245 9179060.80 9179060.80 0.0418 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396EL3 S6XOOCT0IEG5ABCC6L87 US313396EL34 U.S. Government Agency Debt Y 2019-04-17 2019-04-17 2019-04-17 N N N 0.0245 10611510.83 10611510.83 0.0483 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396ET6 S6XOOCT0IEG5ABCC6L87 US313396ET69 U.S. Government Agency Debt Y 2019-04-24 2019-04-24 2019-04-24 N N N 0.0245 3487347.50 3487347.50 0.0159 N N Y N Federal Home Loan Mortgage Corp. Federal Home Loan Mortgage Corp. 313396FN8 S6XOOCT0IEG5ABCC6L87 US313396FN80 U.S. Government Agency Debt Y 2019-05-13 2019-05-13 2019-05-13 N N N 0.0247 5273992.90 5273992.90 0.0240 N N N N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588CS2 B1V7KEBTPIMZEU4LTD58 US313588CS29 U.S. Government Agency Debt Y 2019-03-06 2019-03-06 2019-03-06 N N N 0.0241 5598146.40 5598146.40 0.0255 N N Y N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588CY9 B1V7KEBTPIMZEU4LTD58 US313588CY96 U.S. Government Agency Debt Y 2019-03-12 2019-03-12 2019-03-12 N N N 0.0241 5795783.40 5795783.40 0.0264 N N Y N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588CZ6 B1V7KEBTPIMZEU4LTD58 US313588CZ61 U.S. Government Agency Debt Y 2019-03-13 2019-03-13 2019-03-13 N N N 0.0241 4996035.00 4996035.00 0.0228 N N Y N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588DN2 B1V7KEBTPIMZEU4LTD58 US313588DN23 U.S. Government Agency Debt Y 2019-03-26 2019-03-26 2019-03-26 N N N 0.0242 8985123.00 8985123.00 0.0409 N N Y N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588DU6 B1V7KEBTPIMZEU4LTD58 US313588DU65 U.S. Government Agency Debt Y 2019-04-01 2019-04-01 2019-04-01 N N N 0.0245 9451347.68 9451347.68 0.0431 N N Y N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588EB7 B1V7KEBTPIMZEU4LTD58 US313588EB75 U.S. Government Agency Debt Y 2019-04-08 2019-04-08 2019-04-08 N N N 0.0245 5984736.00 5984736.00 0.0273 N N Y N Federal National Mortgage Assoc. Federal National Mortgage Assoc. 313588EJ0 B1V7KEBTPIMZEU4LTD58 US313588EJ02 U.S. Government Agency Debt Y 2019-04-15 2019-04-15 2019-04-15 N N N 0.0245 2990961.00 2990961.00 0.0136 N N Y N Goldman Sachs & Co. LLC Goldman Sachs & Co. LLC 2.550000% FOR8UP27PHTHYVLBNG30 0000769993 318991007_2.55_0301 U.S. Treasury Repurchase Agreement, if collateralized only by U.S. Treasuries (including Strips) and cash Y N U.S. Treasury Bill 254900HROIFWPRGM1V77 2022-07-31 1.875000 12104300.00 11879962.25 U.S. Treasuries (including strips) Y 2019-03-01 2019-03-01 2019-03-01 N N N 0.0255 11647000.00 11647000.00 0.0531 N Y Y N JPMorgan Chase JPMorgan Chase 2.600000% 8I5DZWZKVSZI1NUHU748 0001168163 446199002_2.60_0301 U.S. Treasury Repurchase Agreement, if collateralized only by U.S. Treasuries (including Strips) and cash Y N U.S. Treasury Bill 254900HROIFWPRGM1V77 2022-09-30 1.875000 100.00 98.58 U.S. Treasuries (including strips) U.S. Treasury Bill 254900HROIFWPRGM1V77 2020-11-30 2.750000 4022900.00 4063078.51 U.S. Treasuries (including strips) U.S. Treasury Bill 254900HROIFWPRGM1V77 2021-07-31 1.125000 100.00 96.83 U.S. Treasuries (including strips) U.S. Treasury Bill 254900HROIFWPRGM1V77 2019-04-30 1.250000 17000.00 17033.82 U.S. Treasuries (including strips) Y 2019-03-01 2019-03-01 2019-03-01 N N N 0.0260 4000000.00 4000000.00 0.0182 N Y Y N U.S. Treasury Bill U.S. Treasury Bill 912796QZ5 254900HROIFWPRGM1V77 US912796QZ54 U.S. Treasury Debt Y 2019-03-07 2019-03-07 2019-03-07 N N N 0.0236 2199146.58 2199146.58 0.0100 N Y Y N U.S. Treasury Bill U.S. Treasury Bill 912796RQ4 254900HROIFWPRGM1V77 US912796RQ47 U.S. Treasury Debt Y 2019-05-16 2019-05-16 2019-05-16 N N N 0.0244 1840665.71 1840665.71 0.0084 N Y Y N U.S. Treasury Bill U.S. Treasury Bill 912796UR8 254900HROIFWPRGM1V77 US912796UR82 U.S. Treasury Debt Y 2019-03-05 2019-03-05 2019-03-05 N N N 0.0238 5598540.86 5598540.86 0.0255 N Y Y N U.S. Treasury Bill U.S. Treasury Bill 912796UV9 254900HROIFWPRGM1V77 US912796UV94 U.S. Treasury Debt Y 2019-04-02 2019-04-02 2019-04-02 N N N 0.0245 9080478.32 9080478.32 0.0414 N Y Y N U.S. Treasury Bill U.S. Treasury Bill 912796XJ3 254900HROIFWPRGM1V77 US912796XJ30 U.S. Treasury Debt Y 2019-03-01 2019-03-01 2019-03-01 N N N 0.0001 6000000.00 6000000.00 0.0273 N Y Y N MFS Series Trust I 2019-03-07 /s/Kino Clark Kino Clark Assistant Treasurer