2014 Annual Attachment O Stakeholder Meeting Ameren Missouri August 18,2014

2 AGENDA Primary purpose is to review AMMO Pricing Zone Historical 2013 Transmission Rate Calculations which became effective June 1, 2014 Background on Attachment O,GG & MM Overview of MTEP Ameren Missouri Rate Inputs New Rate Protocols Comparison to Previous Revenue Requirement 2014 AMMO Pricing Zone NITS Charge

3 AMEREN MISSOURI Ameren Missouri is a transmission-owning subsidiary of Ameren Corporation, as well as a MISO Transmission Owner (TO) Ameren Illinois and Ameren Transmission Company of Illinois (ATXI) are two other Ameren subsidiaries that are MISO TOs. ATXI was formed to build and own new regional transmission projects such as the MISO Multi-Value Projects Ameren Missouri will continue to build and own traditional reliability projects needed to meet local needs and continue to maintain its existing transmission system Ameren Missouri is currently building a new local reliability project in Southeast Missouri. Ameren Missouri is the only MISO Transmission Owner in the AMMO pricing zone.

4 MISO ATTACHMENTS O & GG Calculate rates for Schedules 9, 26 & 26-A Attachment GG - Schedule 26 Attachment MM – Schedule 26-A Attachment O - net revenue requirement billed under Schedule 9 Schedules 26 and 26-A are billed by MISO Schedule 9 is billed by Ameren

5 MISO ATTACHMENT GG Cost Recovery for certain Network Upgrades Eligible projects Market Efficiency Generator Interconnections Cost shared based upon project type MISO-wide based on load Subregional based on LODF (Line Outage Distribution Factor) Ameren Missouri has three Attachment GG projects completed One additional project under construction These projects were approved by MISO under prior Tariff provisions which allowed limited cost sharing for certain reliability projects Attachment MM is very similar to Attachment GG Applies to MISO Multi-Value Projects, but is not applicable to Ameren Missouri since it is not building or developing any MVPs.

6 MISO ATTACHMENT O & GG All transmission costs included in Attachment O calculation Schedule 9 based on net revenue requirement – reductions for: Any costs recovered in Schedules 26 & 26-A Revenue Credits Point-to-Point revenue in Schedules 7 & 8 Rental revenue Revenue from generator interconnections Questions on Tariffs?

7 MISO TRANSMISSION EXPANSION PLAN (MTEP) Developed on an annual basis building upon previous analysis MISO, Transmission Owners & Stakeholders Includes subregional planning meetings MTEP goals Ensure the reliability of the transmission system Ensure compliance with NERC Standards Provide economic benefits, such as increased market efficiency Facilitate public policy objectives, such as meeting Renewable Portfolio Standards Address other issues or goals identified through the stakeholder process Multiple future scenarios analyzed End result – comprehensive, cohesive plan for MISO footprint MTEP approved by MISO Board of Directors

8 AMMO RATE INPUTS Rates calculated using prior year FERC Form 1 data (historical calculation) Rate base items based on Dec 31 ending balances Only wholesale customers pay the Schedule 9 Rate in AMMO –About 6% of load Ameren Missouri retail customers –Transmission facilities & costs included in bundled rates set by MoPSC –Pay for other MISO transmission related costs through the FAC Note that some Transmission Owners’ rate calculations are different –Rates are initially set based on projected data –Annual True-up calculation to reflect actual costs reported in Form 1

9 NEW RATE PROTOCOLS On May 16, 2013, FERC issued order EL12-35 concerning required modifications to MISO rate protocols. The order requires MISO and the MISO Transmission Owners to modify the formula rate protocols to Allow for increased scope of participation by Interested Parties Allow for increased transparency concerning the implementation of the formula rate, Define a process for information exchange Allow for provision of additional information; and well-defined and clearly- structured challenge procedure Require MISO and the MISO Transmission Owners to make an annual informational filing with FERC The TOs filed compliance filings on September 13, 2013 Requested an effective date of January 1, 2014 The protocols will be applicable for the first subsequent Annual Update and Annual True-Up, which will take place on June 1, 2014

10 NEW RATE PROTOCOLS On March 20, 2014, FERC issued order ER concerning additional required modifications to MISO rate protocols. The TOs filed compliance filings on May 19, 2014 The protocols were applicable for the first subsequent Annual Update and Annual True-Up, which took place on June 1, 2014

11 NEW PROTOCOL TIMELINE Date Action (Historical) June 1  Posting of annual update  Information exchange period begins.  Review period begins. September 1  Deadline for annual meeting November 1  Deadline for joint meeting on regional cost-shared projects December 1  Deadline for Interested Parties to submit information requests January 10  Deadline for Transmission Owners to respond to information requests January 31  Deadline for Interested Parties to submit Informal Challenges February 28  Deadline for Transmission Owners to respond to Informal Challenges  Any rate changes agreed to by the Transmission Owner will be included in the Information Filing and will be reflected in the Annual Update for the following Rate Year. March 15  Transmission Owners submit informational filing to the Commission. March 31  Deadline for Interested Parties to file Formal Challenge at the Commission

12 AMMO Revenue Requirement June 2013 vs June 2014 Filings

13 AMMO JUNE 2014 FILING Rate Base Page.Line Jun-13Jun-14ChangePercent 2.6Total Gross Plant776,445,309843,566,30867,120,9999% 2.12Total Accum Depreciation269,340,644282,535,08013,194,4365% 2.18TOTAL NET PLANT507,104,666561,031,22853,926,56311% ADJUSTMENTS TO RATE BASE 2.20 Account No ,790, ,726,236-19,935,37715% 2.21 Account No ,122,036-6,995,9361,126,101-14% 2.22 Account No. 1902,918,0805,296,9172,378,83782% 2.25 Land Held for Future Use762,157799,48037,3235% 2.26 CWC3,098,4213,090,433-7,9880% 2.27 Materials & Supplies5,034,7216,883,0991,848,37837% 2.28 Prepayments847,278901,28754,0096% TOTAL ADJUSTMENTS-127,252, ,750,957-14,498,71711% 2.30TOTAL RATE BASE379,852,426419,280,27239,427,84510%

14 AMMO JUNE 2014 FILING Expenses Page.Line Jun-13Jun-14ChangePercent O&M 3.1 Transmission48,403,47056,001,5577,598,08716% 3.1a Less LSE Expenses7,206,9326,469, ,703-10% 3.2 Less Account 56522,683,67530,809,1608,125,48536% 3.3 A&G6,135,7525,704, ,691-7% 3.4 Less FERC Annual Fees000N/A 3.5 Less EPRI, ect.559,298445, ,851-20% 3.5a Plus Trans. Reg. Comm. Exp9,63967,17957,540597% 3.7Transmission Lease Payments688,410674,502-13,908-2% 3.8TOTAL O&M24,787,36724,723,464-63,9030% 3.12TOTAL DEPRECIATION17,210,30918,065,642855,3335% TAXES 3.13 Payroll568,377477,114-91,263-16% 3.16 Property7,105,9077,898,117792,21111% 3.18 Other103,47887,186-16,291-16% 3.27 Income Taxes14,594,55116,529,7981,935,24613% TOTAL TAXES22,372,31324,992,2152,619,90212% TOTAL EXPENSES64,369,99067,781,3223,411,3325%

15 AMMO JUNE 2014 FILING Capital Structure Capital Structure Page.Line $%CostWeighted 4.27 Long Term Debt3,709,271,00048% Preferred Stock80,759,5001% Common Stock3,973,425,62651% Total7,763,456,126100% Capital Structure Page.Line $%CostWeighted 4.27 Long Term Debt3,465,276,00046% Preferred Stock80,759,5001% Common Stock3,912,960,92752% Total7,458,996,427100% Change in Return0.1846%

16 AMMO JUNE 2014 FILING Revenue Requirement Page.Line Jun-13Jun-14ChangePercent 2.30TOTAL RATE BASE379,852,426419,280,27239,427,84510% 4.30Rate of Return9.09%9.27%0.18%2% 3.28Return34,518,21438,875,2204,357,00613% Total Expenses64,369,99067,781,3223,411,3325% 3.29TOTAL GROSS REV. REQ.98,888,204106,656,5427,768,3388% 3.30Less ATT. GG Adjustment9,037,5818,879, ,734-2% 3.30aLess ATT. MM Adjustment000N/A 3.31GROSS REV. REQ. UNDER ATT. O89,850,62397,776,6957,926,0729%

17 AMMO JUNE 2014 FILING Net Revenue Requirement Page.Line Jun-13Jun-14ChangePercent 1.1Gross Revenue Requirement89,850,62397,776,6957,926,0729% 1.6Total Revenue Credits8,417,4049,091,089673,6858% 1.7NET REVENUE REQUIREMENT81,433,21988,685,6067,252,3879%

18 AMMO JUNE 2014 FILING Schedule 9 Rate Calculation Page.Line ChangePercent 1.7Net Revenue Requirement81,433,21988,685,6067,252,3879% 1.15Ameren Missouri Divisor6,847,8976,900,30752,4101%.Annual Cost ($/kW/Yr) %.Network & P-to-P Rate ($/kW/Mo) %

19 AMMO JUNE 2014 FILING Attachment GG Calculation - Page 1 (1)(2)(3)(4) Attachment O LinePage, Line, Col.TransmissionAllocator No. 1Gross Transmission Plant - Total Attach O, p 2, line 2 col 5 (Note A)829,297,144 2Net Transmission Plant - Total Attach O, p 2, line 14 and 23b col 5 (Note B) 553,300,739 O&M EXPENSE 3Total O&M Allocated to TransmissionAttach O, p 3, line 8 col 524,723,464 4Annual Allocation Factor for O&M(line 3 divided by line 1 col 3)2.98% GENERAL AND COMMON (G&C) DEPRECIATION EXPENSE 5Total G&C Depreciation Expense Attach O, p 3, lines 10 & 11, col 5 (Note H)618,458 6Annual Allocation Factor for G&C Depreciation Expense(line 5 divided by line 1 col 3)0.07% TAXES OTHER THAN INCOME TAXES 7Total Other TaxesAttach O, p 3, line 20 col 58,462,417 8Annual Allocation Factor for Other Taxes(line 7 divided by line 1 col 3)1.02% 9Annual Allocation Factor for ExpenseSum of line 4, 6, and 84.08% INCOME TAXES 10Total Income TaxesAttach O, p 3, line 27 col 516,529,798 11Annual Allocation Factor for Income Taxes(line 10 divided by line 2 col 3)2.99% RETURN 12Return on Rate BaseAttach O, p 3, line 28 col 538,875,220 13Annual Allocation Factor for Return on Rate Base(line 12 divided by line 2 col 3)7.03% 14Annual Allocation Factor for ReturnSum of line 11 and %

20 AMMO JUNE 2014 FILING Attachment GG Calculation - Page 2 (1)(2)(3)(4)(5)(6)(7)(8) Line No. Project Name MTEP Project Number Project Gross Plant Annual Allocation Factor for Expense Annual Expense Charge Project Net Plant Annual Allocation Factor for Return Annual Return Charge (Note C)(Page 1 line 9)(Col. 3 * Col. 4)(Note D) (Page 1 line 14)(Col. 6 * Col. 7) 1a Big River-Rockwood 138 kV 152 $ 19,927, %$812, $ 19,228, %$1,925, b Reconductor Sioux-Huster-1 and kV 1240 $ 15,481, %$631, $ 14,782, %$1,480, c Gray Summit : 2nd 345/138 kV Transformer 2061 $ 22,610, %$921, $ 21,204, %$2,123, (1)(2)(9)(10)(11)(12) Line No. Project Name MTEP Project Number Project Depreciation Expense Annual Revenue Requirement True-Up Adjustment Network Upgrade Charge (Note E)(Sum Col. 5, 8 & 9)(Note F) Sum Col. 10 & 11 (Note G) 1a Big River-Rockwood 138 kV 152$293,785$3,031, $ -3,031,514 1b Reconductor Sioux-Huster-1 and kV 1240$284,683$2,396, $ -2,396,017 1c Gray Summit : 2nd 345/138 kV Transformer 2061$407,350$3,452, $ -3,452,315 2Annual Totals $8,879,847$0$8,879,847 3Rev. Req. Adj For Attachment O $8,879,847

21 AMEREN MISSOURI Significant Line Expansion Projects Not in Service Project NameTotal CostISDMTEPMISO ID#MTEP Description Cape Girardeau Electric Reliability Project (Northwest Cape Area 345/161 kV Substation) $50 M2016MTEP Install 560 MVA, 345/161 kV Transformer. Provide 345 kV supply from 11 mile 345 kV line extension from Lutesville Substation

22 MISO WEB LINKS Transmission Pricing - Attachments O, GG & MM Information s/Pages/TransmissionPricing.aspxhttps:// s/Pages/TransmissionPricing.aspx Ameren OASIS MTEP 13 Pages/MTEP13.aspxhttps:// Pages/MTEP13.aspx MTEP 14 Pages/MTEP14.aspxhttps:// Pages/MTEP14.aspx Schedule 26 & 26-A Indicative Charges Pages/MTEPStudies.aspxhttps:// Pages/MTEPStudies.aspx

QUESTIONS?