Transmission Rate True-Up Stakeholder Meeting Update

2018 Attachment O True-Up Stakeholder Meeting Ameren Illinois Company July 17, 2019

AGENDA Purpose is to review AIC 2018 Transmission Rate True-Up Calculations Protocol Timeline ER18-2322 filing to remove double averaging from ADIT proration ROE Complaint Cases and Impact on True-up calculations 2018 True-Up Calculation Total Revenue Requirement Comparison Projected vs Actual Attachment O/Schedule 9 True-up Attachment GG/Schedule 26 True-up Attachment MM/Schedule 26-A True-up 2018 Significant Projects Placed In Service An additional meeting will held to review the 2020 Projected Transmission Rate calculations. 2

PROTOCOL TIMELINE Schedule Date (Forward-Looking Protocols) June 1 Posting of annual true-up for prior year September 1 Deadline for annual true-up meeting September 1 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 3

ER18-2322 FILING TO REMOVE DOUBLE AVERAGING Docket ER18-2322 FERC Order on December 20, 2018 Effective January 1, 2019 but applicable to 2018 TU Removed double averaging The term double averaging or two-step averaging methodology refers to the application of the IRS proration methodology together with an additional averaging step 4

ROE COMPLAINTS MISO ROE Complaints 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 may 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%) 5

ROE COMPLAINTS MISO ROE for the 2018 True-Up 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 completed by Ameren Schedule 9 Refund amounts and supporting documents are posted on Ameren s OASIS 6

AIC Revenue Requirement Comparison Projected 2018 vs Actual 2018 7

AIC 2018 RATE BASE 2018 Projection 2,603,238,875 541,401,482 2,061,837,394 2018 Actual 2,588,885,860 520,229,120 2,068,656,740 Change -14,353,016 -21,172,362 6,819,346 Percent Page.Line 2.6 2.12 2.18 Total Gross Plant Total Accum Depreciation TOTAL NET PLANT -1% -4% 0% 100% CWIP RECOVERY 2.18a 0 0 0 N/A ADJUSTMENTS TO RATE BASE Account No. 282 Account No. 283 Account No. 190 Account No. 255 Land Held for Future Use CWC Materials & Supplies Prepayments TOTAL ADJUSTMENTS 0 N/A 1% -54% -42% N/A -7% -13% 1% 4% 2% 2.20 2.21 2.22 2.23 2.25 2.26 2.27 2.28 -520,626,834 -20,366,151 44,543,127 -523,310,107 -9,294,569 26,017,226 -2,683,274 11,071,582 -18,525,900 0 0 0 2,438,967 6,655,963 14,460,942 1,946,709 -470,947,278 2,265,618 5,810,137 14,623,771 2,024,430 -481,863,494 -173,349 -845,826 162,830 77,721 -10,916,217 TOTAL RATE BASE 2.30 1,590,890,116 1,586,793,245 -4,096,871 0% 8

AIC 2018 EXPENSES 2018 Projection 2018 Actual Change Percent Page.Line O&M Transmission Less LSE Expenses Less Account 565 A&G Less FERC Annual Fees Less EPRI, ect. Plus Trans. Reg. Comm. Exp TOTAL O&M 3.1 3.1a 3.2 3.3 3.4 3.5 3.5a 3.8 59,219,133 1,444,779 21,760,225 17,175,591 56,530,813 1,750,576 22,254,190 14,168,887 -2,688,320 305,797 493,965 -3,006,705 -5% 21% 2% -18% N/A 58% -49% -13% 0 0 0 227,761 285,746 53,247,705 359,935 146,099 46,481,097 132,174 -139,647 -6,766,608 TOTAL DEPRECIATION 3.12 49,739,417 48,673,405 -1,066,012 -2% TAXES Payroll Property Other Income Taxes TOTAL TAXES 0 N/A -12% 6% 24% -19% -17% 3.13 3.16 3.18 3.27 911,941 1,468,525 510,091 35,529,571 38,420,128 801,985 1,554,105 633,515 28,955,978 31,945,582 -109,956 85,580 123,424 -6,573,594 -6,474,546 TOTAL EXPENSES 141,407,250 127,100,084 -14,307,166 -10% 9

AIC 2018 CAPITAL STRUCTURE 2018 Projection $ % Cost Weighted 0.0242 0.0005 0.0559 0.0806 Page.Line 4.27 4.28 4.29 4.30 Long Term Debt Preferred Stock Common Stock Total 3,011,659,846 61,632,375 3,280,381,766 6,353,673,988 47% 1% 52% 100% 0.0511 0.0491 0.1082 2018 Actual $ % Cost Weighted 0.0234 0.0005 0.0555 0.0794 Page.Line 4.27 4.28 4.29 4.30 Long Term Debt Preferred Stock Common Stock Total 3,033,967,538 61,632,375 3,260,645,207 6,356,245,121 48% 1% 51% 100% 0.0490 0.0491 0.1082 Change in Return -0.1210% 10

AIC 2018 TOTAL REVENUE REQUIREMENT 2018 Projection 1,590,890,116 2018 Actual 1,586,793,245 Change -4,096,871 -0.12% -2,250,462 Percent Page.Line 2.30 4.30 3.28 TOTAL RATE BASE Rate of Return Return 0% -2% -2% 8.06% 7.94% 128,197,463 125,947,002 Total Expenses TOTAL GROSS REV. REQ. 141,407,250 269,604,713 127,100,084 253,047,086 -14,307,166 -16,557,628 -10% -6% 3.29 3.30 3.30a 3.31 Less ATT. GG Adjustment Less ATT. MM Adjustment GROSS REV. REQ. UNDER ATT. O 14,560,941 12,400,665 242,643,107 13,581,675 11,697,368 227,768,043 -979,266 -703,297 -14,875,065 -7% -6% -6% 11

AIC 2018 NET REVENUE REQUIREMENT FOR SCHEDULE 9 2018 Projection 242,643,107 13,569,507 2018 Actual 227,768,043 12,795,919 Change -14,875,065 -773,588 Percent Page.Line 1.1 1.6 Gross Revenue Requirement Total Revenue Credits -6% -6% 1.6a 1.6b 1.6c 1.6d 1.6e Historic Year Actual ATRR Projected ATRR from Prior Year Prior Year ATRR True-Up Prior Year Divisor True-Up Interest on Prior Year True-Up 208,996,125 204,663,896 4,332,229 3,530,885 131,345 208,996,125 204,663,896 4,332,229 3,530,885 131,345 0 0 0 0 0 0% 0% 0% 0% 0% 1.7a 1.7b 1.7 NET REVENUE REQUIREMENT Prairie Power AIC Adjusted Revenue Requirement 237,068,060 222,966,583 -14,101,477 -6% N/A -6% 0 0 0 237,068,060 222,966,583 -14,101,477 . 12

AIC 2018 ATTACHMENT O TRUE-UP FOR SCHEDULE 9 Attachment O 2018 True-up Calculation (Schedule 9) Prior Period Adjustments 1/ 2018 $222,966,583 Revised True Up $222,965,988 -$595 Net Actual 2018 Rev Req (Actual Attach O, Pg 1, Line 7) $237,068,060 $237,068,060 Net Projected 2018 Rev Req (Projected Attach O, Pg 1, Line 7) Under/(Over) Collection of 2018 Net Rev Req ($14,101,477) ($595) ($14,102,072) 7,199,027 7,176,333 (22,694) 7,199,027 7,176,333 (22,694) Historic Year Actual Divisor for Transmission Owner (Attach O, Pg 1, Line 15) Proj'd Yr Divisor for Transmission Owner (Projected Attach O, Pg 1, Line 15) Difference between Historic & Projected Yr Divisor Prior Year Projected Annual Cost ($ per kw per yr) $33.0347 $33.0347 Under/(Over) Collection of 2018 Divisor True-up ($749,689) $0 ($749,689) Total Under/(Over) Recovery ($14,851,166) ($595) ($14,851,761) Monthly Interest Rate (Over collection = FERC rate, Under collection = company rate) Interest For 24 Months 0.3900% ($1,390,069) ($96) ($1,390,165) Total 2018 Attachment O True-up Under/(Over) Recovery (To be included in Projected 2020) ($16,241,235) ($691) ($16,241,926) 1/ Reflects adjustments agreed to as a result of the formal challenge process related to the 2016 true-up. See WP 22 Prior Period Adj tab for details. 13

AIC 2018 ATTACHMENT GG TRUE-UP BY PROJECT (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k) Actual Projected Annual Revenue Requirement 1 Projected Attachment GG Attachment GG Revenues Allocated to Projects 1 [Col. (d), line 1 x (Col. (e), line 2x / Actual Annual Revenue Requirement 1 Actual Attachment GG True-Up Adjustment Principal Under/(Over) Applicable Interest Rate on Under/(Over) True-Up Adjustment Interest Under/(Over) MTEP Project Number Actual Total True-Up Adjustment Line No. Project Name Attachment GG Revenues Col. (h) x Col. (i) p 2 of 2, Col. 102 Col. (e), line 3)]2 p 2 of 2, Col. 102 x 24 months 2 Col. (g) - Col. (f) Line 5 Col. (h) + Col. (j) 1 Actual Attachment GG revenues for True-Up Year 1 $ 15,300,758 2a Wood River-Roxford 1502 138kV line 728 368,284 386,996 329,863 (57,133) 0.3900% (5,348) (62,481) 2b Sidney-Paxton 138kV Reconductor 18 miles 870 646,862 679,728 586,367 (93,361) 0.3900% (8,739) (102,100) 2c Coffeen Plant-Coffeen, North - 2nd. Bus tie 2829 636,044 668,360 589,410 (78,950) 0.3900% (7,390) (86,340) 2d Latham - Oreana 8.5 mile 345kV line 2068 2,774,626 2,915,600 2,592,068 (323,532) 0.3900% (30,283) (353,815) 2e Brokaw-S. Bloom 345/138kV Trans & 345kV line 2069 3,663,272 3,849,397 3,429,130 (420,267) 0.3900% (39,337) (459,604) 2f Fargo-Mapleridge-20 mile 345kV line & New Sub 2472 6,471,853 6,800,677 6,054,837 (745,840) 0.3900% (69,811) (815,651) 3 Subtotal $ 14,560,941 $ 15,300,758 $ 13,581,675 4 Under/(Over) Recovery $ (1,719,083) $ (160,908) $ (1,879,991) 5 Applicable Interest rate per month (expressed to four decimal places) Interest Rate to be updated through July 2019 0.3900% 1 Amount excludes True-Up Adjustment, as reported in True-Up Year projected Attachment GG, page 2, column 11. Rounded to whole dollars. 2 14

AIC 2018 ATTACHMENT MM TRUE-UP BY PROJECT (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k) Actual Projected Annual Revenue Attachment MM Revenues Allocated Actual Annual Revenue True-Up Adjustment Principal Applicable Interest Rate on True-Up Adjustment Interest MTEP Project Actual Total True-Up Line Project Attachment MM Requirement 1 Projected Attachment MM to Projects 1 [Col. (d), line 1 x (Col. (e), line 2x / Requirement 1 Actual Attachment MM No. Name Number Revenues Under/(Over) Under/(Over) Under/(Over) Adjustment Col. (h) x Col. (i) p 2 of 2, Col. 142 Col. (e), line 3)]2 p 2 of 2, Col. 142 x 24 months 2 Col. (g) - Col. (f) Line 5 Col. (h) + Col. (j) 1 Actual Attachment MM revenues for True-Up Year 1 $ 11,560,012 2a 2b Pana-Sugar Creek - Plant in Service Pana-Sugar Creek - CWIP 2237 2237 $ - $ 4,771,290 - - - 0.1931% 0.1931% - - 4,447,839 4,500,817 52,978 2,455 55,433 2c 2d Sidney-Rising - Plant in Service Sidney-Rising - CWIP 2239 2239 $ - $ 810,928 - - - 0.1931% 0.1931% - - 755,954 762,946 6,992 324 7,316 2e 2f Palmyra-Pawnee - CWIP Palmyra-Pawnee - Plant in Service 3017 3017 $ - $ 4,373,487 - - - 0.1931% 0.1931% - - 4,077,004 4,123,569 46,565 2,158 48,723 2g 2h Fargo-Galesburg-Oak Grove - Plant 2i Pawnee-Pana - CWIP 2j Pawnee-Pana - Plant in Service Fargo-Galesburg-Oak Grove - CWIP 3022 3022 3169 3169 $ - $ 420,361 $ - $ 2,024,600 - - - 0.1931% 0.1931% 0.1931% 0.1931% - - 391,864 396,260 4,396 204 - 4,600 - - - - 1,887,350 1,913,776 26,426 1,225 27,651 3 Subtotal $ 12,400,666 $ 11,560,011 $ 11,697,368 4 Under/(Over) Recovery $ 137,357 $ 6,366 $ 143,723 5 Applicable Interest rate per month (expressed to four decimal places) Interest Rate to be updated through July 2019 0.1931% 1 Amount excludes True-Up Adjustment, as reported in True-Up Year projected Attachment MM, page 2, column 15. 2 Rounded to whole dollars. 15

AIC 2018 ATTACH GG & MM TRUE-UP FOR SCHEDULE 26 & 26-A Attachment GG 2018 True-up Calculation ( Schedule 26) Actual 2018 Attachment GG Rev Req (Actual Attach GG, pg 2, col 10) 1 $ 13,581,675 $15,300,758 Actual Attachment GG Revenues Received for 20181 Under/(Over) Recovery of 2018 GG Rev Req ($1,719,083) Monthly Interest Rate (Over collection = FERC rate, Under collection = company rate) Interest For 24 Months 0.3900% ($160,906) Total 2018 Attachment GG True-up Under/(Over) Recovery (To be included in Projected 2020) ($1,879,989) 1 Amount excludes True-Up Adjustment, as reported in 2018 projected Attachment GG, page 2, column 11. Attachment MM 2018 True-up Calculation (Schedule 26-A) Actual 2018 Attachment MM Rev Req (Actual Attach MM, pg 2, col 14) 1 $ 11,697,368 $11,560,012 Actual Attachment MM Revenues Received for 2018 Under/(Over) Recovery of 2018 MM Rev Req $137,356 Monthly Interest Rate (Over collection = FERC rate, Under collection = company rate) Interest For 24 Months 0.1931% $6,366 Total 2018 Attachment MM True-up Under/(Over) Recovery (To be included in Projected 2020) $143,722 1 Amount excludes True-Up Adjustment, as reported in 2018 projected Attachment MM, page 2, column 15. 16

2018 SIGNIFICANT TRANSMISSION PROJECTS ADDED TO PLANT Project Name Total Cost ($ Millions) IT089 - Decatur-Bloomington Line Rebuild CS014 - NERC CIP V5 - LOW IT055 - Ramsey East Ring Bus IT031 - Cahokia-Dupo Ferry-Buck Knob IT132 - Moweaqua - Decatur Route 51 IT133 - Hennepin-Woodhall CS023 - Intelligrid - Core Medium IT099 - Albion South - Olney North IT061 - Neoga South Expansion IT078 - Greenville McCord Ring Bus IT138 - Lawrenceville-Olney N IT066 - Prest Ring Bus IT100 - Muddy - Norris City North IT105 - Mt. Vernon South - Ina MT016 - Venice-Campbell River Crossing IT139 - WDHL-SPBA Rebuild IT064 - Tabor Ring Bus IT088 - Newton Switchyard IT056 - Gifford Ring Bus IT040 - Hull Ring Bus CS012 - Intelligrid - Core High IT074 - Herzog Ring Bus IT101 - Baldwin-Prairie States IT058 - Prairie State BAAH 26.3 18.0 18.0 16.5 13.2 13.2 12.9 11.0 11.0 10.9 10.3 9.5 9.2 8.9 8.6 7.8 7.4 7.2 7.0 6.7 6.6 6.3 5.8 5.0 17

ADDITIONAL INFORMATION Additional questions can be sent to Ameren at: MISOFormulaRates@ameren.com MISO Web Links Transmission Pricing - Attachments O, GG & MM Information https://www.misoenergy.org/markets-and-operations/settlements/ts-pricing/#t=10&p=0&s=&sd= Ameren OASIS http://www.oasis.oati.com/AMRN/index.html MTEP 18 https://www.misoenergy.org/planning/planning/mtep-2018-/ MTEP 17 https://www.misoenergy.org/planning/planning/mtep-2017/#t=10&p=0&s=FileName&sd=desc Schedule 26 & 26-A Indicative Charges https://www.misoenergy.org/planning/planning/schedule-26-and-26a-indicative-reports/ 18