2019 Attachment O Projection Stakeholder Meeting Ameren Transmission Company of Illinois September 25, 2018

Purpose is to review 2019 Projected Transmission Rate Calculations Agenda Purpose is to review 2019 Projected Transmission Rate Calculations Protocol Timeline ROE Complaint Cases ATXI 2019 Projection Attachment O Attachment MM 2019 AMIL Pricing Zone NITS Charge 2019 MVP Spend ER18-2322 filing to remove double averaging from ADIT proration

(Forward-Looking Protocols) Protocol timeline Date Schedule (Forward-Looking Protocols) June 1 Posting of annual true-up for prior year September 1 Deadline for annual true-up meeting Posting of net projected revenue requirement for following year October 15 Deadline for annual projected rate meeting November 1 Deadline for joint meeting on regional cost-shared projects March 15 Transmission Owners submit informational filing to the Commission

ROE complaints MISO ROE Complaints RTO Adder (ER15-358) 1st Complaint (EL14-12) Covers November 12, 2013 through February 11, 2015 FERC order received September 28, 2016; set the Base ROE at 10.32% Applicable going forward until 2nd complaint order 2nd Complaint (EL15-45) Covers February 12, 2015 through May 11, 2016 Initial decision issued June 30, 2016; recommended Base ROE at 9.70% Additional refunds will be required upon receipt of Final Order RTO Adder (ER15-358) FERC approved a 50 basis point adder for participation in an RTO Effective January 6, 2015, applicable to complaint case refunds after that date and going forward (i.e., total ROE is now 10.82%)

MISO ROE for the 2017 True-Up and 2019 Projection is 10.82% ROE complaints MISO ROE for the 2017 True-Up and 2019 Projection is 10.82% Refunds already provided for EL14-12 Two phase process Phase 1 related to ROE impact on projected rates for forward looking TOs and annual updates for historical TOs. These were settled in February 2017. 2013, 2014 & 2015 projected rates from 11/12/13 to 2/11/15 Phase 2 related to the ROE impact on true-ups calculations for forward looking TOs. These were settled in June 2017. 2013, 2014 & 2015 True-ups included in 2015, 2016 and 2017 projected rates Refunds for Schedules 7, 8, 26, 37, 38, 26A were completed by MISO Refunds for Schedule 9 were processed by Ameren Schedule 9 Refund amounts and supporting documents are posted on Ameren’s OASIS

ATXI Revenue Requirement Projected 2018 vs Projected 2019 (Projected 2018 = Current Effective Calculation at FIT of 21%)

ATXI 2019 Projected Rate Base Page.Line 2018 Projection 2019 Projection Change Percent 2.6 Total Gross Plant 1,287,715,104 1,442,510,559 154,795,455 12% 2.12 Total Accum Depreciation 43,663,636 67,216,186 23,552,550 54% 2.18 TOTAL NET PLANT 1,244,051,468 1,375,294,373 131,242,905 11% 2.18a 100% CWIP RECOVERY 179,259,075 176,840,028 -2,419,047 -1% ADJUSTMENTS TO RATE BASE 2.20 Account No. 282 -210,933,057 -257,682,103 -46,749,046 22% 2.21 Account No. 283 -3,795,167 -3,500,572 294,595 -8% 2.22 Account No. 190 56,643,669 42,249,132 -14,394,537 -25% 2.25 Land Held for Future Use N/A 2.26 CWC 1,841,296 1,792,750 -48,547 -3% 2.27 Materials & Supplies 2.28 Prepayments 386,923 365,285 -21,638 -6% TOTAL ADJUSTMENTS -155,856,335 -216,775,508 -60,919,172 39% 2.30 TOTAL RATE BASE 1,267,454,207 1,335,358,893 67,904,686 5%

ATXI 2019 Projected Expenses Page.Line 2018 Projection 2019 Projection Change Percent O&M 3.1 Transmission 3,022,265 3,354,258 331,993 11% 3.1a Less LSE Expenses N/A 3.2 Less Account 565 3.3 A&G 11,708,106 10,987,742 -720,365 -6% 3.4 Less FERC Annual Fees 3.5 Less EPRI, etc. 26,233 50,877 24,644 94% 3.5a Plus Trans. Reg. Comm. Exp 3.8 TOTAL O&M 14,730,372 14,342,000 -388,372 -3% 3.12 TOTAL DEPRECIATION 28,881,967 28,094,972 -786,995 TAXES 3.13 Payroll 3.16 Property 3,510,160 1,832,000 -1,678,160 -48% 3.18 Other 673,000 631,000 -42,000 3.27 Income Taxes * 30,388,622 31,111,623 723,001 2% TOTAL TAXES 34,571,782 33,574,623 -997,159 TOTAL EXPENSES 78,184,121 76,011,594 -2,172,526 * The 2019 projected income taxes include the adjustments related to Docket ER17-2323 (discussed at 2017 TU meeting).

ATXI 2019 Projected capital structure Capital Structure - 2018 Projection Page.Line $ % Cost Weighted 4.27 Long Term Debt 550,000,000 43.8% 0.0341 0.0149 4.28 Preferred Stock 0.0% - 4.29 Common Stock 706,796,123 56.2% 0.1082 0.0608 4.30 Total 1,256,796,123 100.0% 0.0758 Capital Structure - 2019 Projection 525,000,000 43.9% 0.0348 0.0153 671,302,757 56.1% 0.0607 1,196,302,757 0.0760 Actual Capital Structure Return Hypothetical Capital Structure Return 0.0759 Difference applied to CWIP in Attachment MM (0.0001)

ATXI 2019 Projected total revenue requirement Page.Line 2018 Projection 2019 Projection Change Percent 2.30 TOTAL RATE BASE 1,267,454,207 1,335,358,893 67,904,686 5% 4.30 Rate of Return on ACS 7.58% 7.60% 0.02% 0% 3.28 Return from ACS 96,054,820 101,448,802 5,393,982 6% 2.30a 100% CWIP RECOVERY 179,259,075 176,840,028 -2,419,047 -1% 4.30e Incremental Rate of Return on HCS -0.02% -0.01% 0.01% -52% 3.28a Incremental Return from HCS -31,591 -14,907 16,684 -53% Total Return 96,023,229 101,433,895 5,410,666 Total Expenses 78,184,121 76,011,594 -2,172,526 -3% 3.29 TOTAL GROSS REV. REQ. 174,207,349 177,445,489 3,238,140 2% 3.30 Less ATT. GG Adjustment N/A 3.30a Less ATT. MM Adjustment 166,512,669 170,435,388 3,922,719 3.31 GROSS REV. REQ. UNDER ATT. O 7,694,680 7,010,101 -684,579 -9%

Atxi 2019 Projected Net Revenue Requirement & True-up Page.Line 2018 Projection 2019 Projection Change Percent 1.1 Gross Revenue Requirement 7,694,680 7,010,101 -684,579 -9% 1.6 Total Revenue Credits 839,201 950,316 111,115 13% 1.6a Historic Year Actual ATRR 9,142,207 8,061,139 (1,081,068) -12% 1.6b Projected ATRR from Prior Year 8,608,134 9,052,295 444,161 5% 1.6c Prior Year ATRR True-Up 534,073 (991,156) (1,525,229) -286% 1.6d Prior Year Divisor True-Up 148,506 564,562 416,055 280% 1.6e Interest on Prior Year True-Up 11,746 (34,431) (46,177) -393% 1.7 NET REVENUE REQUIREMENT 7,549,805 5,598,760 -1,951,045 -26%

ATXI 2017 Attachment O true-uP Attachment O 2017 True-up calculation (Schedule 9)   Net Actual 2017 Rev Req (Actual Attach O, Pg 1, Line 7) $8,061,139 Net Projected 2017 Rev Req (Projected Attach O, Pg 1, Line 7) $9,052,295 Under/(Over) Collection of 2017 Net Rev Req ($991,156) Historic Year Actual Divisor for Transmission Owner (Attach O, Pg 1, Line 15) 6,859,419 Proj'd Yr Divisor for Transmission Owner (Projected Attach O, Pg 1, Line 15) 7,315,667 Difference between Historic & Projected Yr Divisor 456,248 Prior Year Projected Annual Cost ($ per kw per yr) $1.2374 Under/(Over) Collection of 2017 Divisor True-up $564,561 Total Under/(Over) Recovery ($426,595) Monthly Interest Rate (Over collection = FERC rate, Under collection = company rate) 0.3363% Interest For 24 Months ($34,431) Total 2017 Attachment O True-up Under/(Over) Recovery (To be included in Projected 2019) ($461,026)

ATXI 2019 Projected attachment MM ATXI Attachment MM Calculation - Page 1

ATXI 2019 Projected attachment MM ATXI Attachment MM Calculation - Page 2 (1) (2) (3) (4) (5) (6) (7) (8) (9) Line No.   Project Name MTEP Project Number Project Gross Plant Project Accumulated Depreciation Transmission O&M Annual Allocation Factor Annual Allocation for Transmission O&M Expense Other Expense Annual Allocation Factor Annual Allocation for Other Expense Annual Expense Charge (Note C) Page 1 line 4 (Col 4 * Col 5) Page 1 line 9 (Col 3 * Col 7) (Col 6 + Col 8) Multi-Value Projects (MVP) 1a Pana-Sugar Creek - CWIP 2237 $51,244,694 $0 5.48% 0.94% $480,222 1b Pana-Sugar Creek - Plant in Service - No HCS $271,779,332 $9,789,349 $536,722 $2,546,888 $3,083,610 1c Pana-Sugar Creek - Land - No HCS $4,491,616 $42,092 1d Sidney-Rising - CWIP 2239 1e Sidney-Rising - Plant in Service - No HCS $79,926,659 $4,703,544 $257,882 $749,006 $1,006,888 1f Sidney-Rising - Land - No HCS $1,285,591 $12,047 1g Adair-Ottumwa - CWIP 2248 $62,030,157 $581,295 1h Adair-Ottumwa - Plant in Service - No HCS $20,999,931 $90,094 $4,940 $196,794 $201,734 1i Adair-Ottumwa - Land - No HCS $1,218,497 $11,419 1j Palmyra-Pawnee - CWIP 3017 1k Palmyra-Pawnee - Plant in Service - No HCS $697,003,776 $27,365,393 $1,500,367 $6,531,735 $8,032,102 1l Palmyra-Pawnee - Land - No HCS $8,834,274 $82,787 1m Fargo-Galesburg-Oak Grove - CWIP 3022 1n Fargo-Galesburg-Oak Grove - Plant in Service - No HCS $122,259,404 $3,941,229 $216,086 $1,145,713 $1,361,799 1o Fargo-Galesburg-Oak Grove - Land - No HCS $3,388,213 $31,751 1p Pawnee-Pana - CWIP 3169 1q Pawnee-Pana - Plant in Service - No HCS $109,637,226 $3,927,771 $215,348 $1,027,428 $1,242,776 1r Pawnee-Pana - Land - No HCS $3,302,135 $30,945 1s Adair-Palmyra - CWIP 3170 $63,565,176 $595,679 1t Adair-Palmyra - Plant in Service - No HCS $44,156,927 $1,753,163 $96,121 $413,802 $509,923 1u Adair-Palmyra - Land - No HCS $769,449 $7,211

ATXI 2019 Projected attachment MM ATXI Attachment MM Calculation - Page 2 (Continued)   (1) (2) (10) (11) (11a) (12) (13) (14) (15) (16) Line No. Project Name MTEP Project Number Project Net Plant Annual Allocation Factor for Return Annual Allocation Factor for HCS Return Annual Return Charge Project Depreciation Expense Annual Revenue Requirement True-Up Adjustment MVP Annual Adjusted Revenue Requirement (Col 3 - Col 4) (Page 1 line 14) (Page 1 line 15) (Note J) (Col 10 * (Col 11 + 11a)) (Note E) (Sum Col. 9, 12 & 13) (Note F) Sum Col. 14 & 15 (Note G) Multi-Value Projects (MVP) 1a Pana-Sugar Creek - CWIP 2237 $51,244,694 8.56% -0.01% $4,384,453 $0 $4,864,675 $1,514,491 $6,379,166 1b Pana-Sugar Creek - Plant in Service - No HCS $261,989,983 0.00% $22,437,730 $5,196,852 $30,718,192 $892,923 $31,611,115 1c Pana-Sugar Creek - Land - No HCS $4,491,616 $384,678 $426,770 $31,064 $457,834 1d Sidney-Rising - CWIP 2239 1e Sidney-Rising - Plant in Service - No HCS $75,223,115 $6,442,368 $1,682,065 $9,131,321 $552,336 $9,683,657 1f Sidney-Rising - Land - No HCS $1,285,591 $110,102 $122,149 $8,850 $130,999 1g Adair-Ottumwa - CWIP 2248 $62,030,157 $5,307,249 $5,888,544 -$1,262,616 $4,625,928 1h Adair-Ottumwa - Plant in Service - No HCS $20,909,837 $1,790,791 $367,244 $2,359,769 1i Adair-Ottumwa - Land - No HCS $1,218,497 $104,356 $115,775 $6,062 $121,837 1j Palmyra-Pawnee - CWIP 3017 -$2,858,043 1k Palmyra-Pawnee - Plant in Service - No HCS $669,638,383 $57,350,153 $12,887,750 $78,270,005 $9,027,679 $87,297,684 1l Palmyra-Pawnee - Land - No HCS $8,834,274 $756,598 $839,385 $61,272 $900,657 1m Fargo-Galesburg-Oak Grove - CWIP 3022 $2,512,877 1n Fargo-Galesburg-Oak Grove - Plant in Service - No HCS $118,318,175 $10,133,179 $2,242,286 $13,737,264 -$1,014,845 $12,722,419 1o Fargo-Galesburg-Oak Grove - Land - No HCS $3,388,213 $290,178 $321,929 $23,169 $345,098 1p Pawnee-Pana - CWIP 3169 -$208,103 1q Pawnee-Pana - Plant in Service - No HCS $105,709,455 $9,053,324 $2,010,086 $12,306,186 $1,959,432 $14,265,618 1r Pawnee-Pana - Land - No HCS $3,302,135 $282,806 $313,751 $22,826 $336,577 1s Adair-Palmyra - CWIP 3170 $63,565,176 $5,438,584 $6,034,263 -$1,378,162 $4,656,101 1t Adair-Palmyra - Plant in Service - No HCS $42,403,764 $3,631,605 $770,773 $4,912,301 $355,825 $5,268,126 1u Adair-Palmyra - Land - No HCS $769,449 $65,898 $73,109 $5,319 $78,428 2 MVP Total Annual Revenue Requirements $170,435,388 $10,252,356 $180,687,744 3 Rev. Req. Adj For Attachment O

ATXI 2017 attachment MM true-up for Schedule 26-A Attachment MM 2017 True-up (Schedule 26-A)   Actual Attachment MM Rev Req for True-Up Year (Actual Attach MM, pg 2, col 14) 1 $159,706,197 Actual Attachment MM Revenues for 20171 $149,703,040 Under/(Over) Recovery of 2017 MM Rev Req $10,003,157 Monthly Interest Rate (Over collection = FERC rate, Under collection = company rate) 0.1038% Interest For 24 Months $249,199 Total 2017 Attachment MM True-up Under/(Over) Recovery $10,252,356 1 Amount excludes True-Up Adjustment, as reported in True-Up Year projected Attachment MM, page 2, column 15.

AMIL Pricing Zone Schedule 9 charge Page.Line 2018 projection 2019 projection Change Percent 1.7 AIC Adjusted Revenue Requirement $237,068,060 $270,941,881 33,873,821 14% ATXI Adjusted Revenue Requirement $7,549,805 $5,598,760 -1,951,045 -26% Hoosier Adjusted Revenue Requirement $1,480,466 0% PPI Adjusted Revenue Requirement $7,864,052 Total Revenue Requirement $253,962,383 $285,885,159 $31,922,776 13% 1.15 Ameren Illinois Divisor 7,176,333 6,942,250 -234,083 -3% Annual Cost ($/kW/Yr) $35.39 $41.18 5.79 16% Network & P-to-P Rate ($/kW/Mo) $2.95 $3.43 0.48 Hoosier became a TO in the AMIL pricing zone effective 7/1/18 and uses historical rate making and therefore won’t update the revenue requirement until 6/1/19. The current revenue requirement for Hoosier is shown above for both years. PPI’s 2019 revenue requirement is not required to be posted until 10/1/18 so the current revenue requirement for PPI is shown above for both years.

Atxi 2019 Projected MVP SPEND Ameren MVPs Ameren Name 2019 CAPEX MTEP #s MTEP Description Illinois Rivers $44.6 million   2237 Pana - Mt. Zion - Kansas - Sugar Creek 345 kV line 3017 Palmyra-Quincy-Meredosia - Ipava & Meredosia-Pawnee 345 kV Line Mark Twain $166.5 million 2248 Adair - Ottumwa 345 3170 Adair-Palmyra 345 kV Line

ER18-2322 filing to remove double averaging Filing made August 28, 2018 Filing addressed Commission June 21, 2018 order in Docket No. EL18-156 The term double averaging or two-step averaging methodology refers to the application of the IRS proration methodology together with an additional averaging step Requested order by October 26th in order to implement for 2019 rates

Appendix - Miso web links Transmission Pricing - Attachments O, GG & MM Information https://www.misoenergy.org/markets-and-operations/ts-pricing Ameren OASIS http://www.oasis.oati.com/AMRN/index.html MTEP 18 https://www.misoenergy.org/planning/transmission-studies-and-reports/#nt=%2Freport-study-analysistype%3AMTEP%2Fmtepdoctype%3AMTEP%20Report%2Fmtepreportyear%3AMTEP18&t=10&p=0&s=&sd= Schedule 26 & 26-A Indicative Charges https://www.misoenergy.org/planning/transmission-studies-and-reports/#nt=%2Freport-study-analysistype%3AMTEP%2Fmtepdoctype%3AMTEP%20Study%2Fmtepstudytype%3AIndicative%20Rate%20Reports&t=10&p=0&s=FileName&sd=desc Additional questions on these topics can be sent to Ameren at: MISOFormulaRates@ameren.com

QUESTIONS?