Financings And Capitalization (Tables)

12 Months Ended

Dec. 31, 2017

Summary Of Long-Term Debt Outstanding

In Millions
	Interest Rate  (%)		Maturity	2017			2016
CMS Energy, including Consumers
CMS Energy, parent only
Senior notes	8.750		2019		$	100		$	300
	6.250		2020			300			300
	5.050		2022			300			300
	3.875		2024			250			250
	3.600		2025			250			250
	3.000		2026			300			300
	2.950		2027			275			275
	3.450		2027			350			-
	4.700		2043			250			250
	4.875		2044			300			300
Total senior notes					$	2,675		$	2,525
Term loan facility	variable	1	2019			180			180
Term loan facility	variable	2	2018			225			-
EnerBank
Certificates of deposit	1.76	3	2018-2026			1,245			1,198
Consumers						5,940			5,661
Total principal amount outstanding					$	10,265		$	9,564
Current amounts						(1,081)			(864)
Net unamortized discounts						(14)			(15)
Unamortized issuance costs						(47)			(45)
Total long-term debt					$	9,123		$	8,640

1Outstanding borrowings bear interest at an annual interest rate of LIBOR plus 0.80 percent (2.37 percent at December 31, 2017).

2Outstanding borrowings bear interest at an annual interest rate of LIBOR plus 0.68 percent (2.28 percent at December 31, 2017).

3The weighted-average interest rate for EnerBank’s certificates of deposit was 1.76 percent at December 31, 2017 and 1.51 percent at December 31, 2016. EnerBank’s primary deposit product consists of brokered certificates of deposit with varying maturities and having a face value of $1,000.

Major Long-Term Debt Transactions

	Principal					Issue/Retirement
	(In Millions)			Interest Rate		Date	Maturity Date
Debt issuances
CMS Energy, parent only
Senior notes		$	350	3.450	%	February 2017	August 2027
Term loan facility1			225	variable		December 2017	December 2018
Total CMS Energy, parent only		$	575
Consumers
First mortgage bonds		$	350	3.950	%	February 2017	July 2047
First mortgage bonds			40	3.180		September 2017	September 2032
First mortgage bonds			125	3.520		September 2017	September 2037
First mortgage bonds			20	3.860		September 2017	September 2052
First mortgage bonds			60	3.180		November 2017	November 2032
First mortgage bonds			210	3.520		November 2017	November 2037
First mortgage bonds			30	3.860		November 2017	November 2052
Total Consumers		$	835
Total CMS Energy		$	1,410
Debt retirements
CMS Energy, parent only
Senior notes2		$	200	8.750	%	December 2017	June 2019
Total CMS Energy, parent only		$	200
Consumers
First mortgage bonds		$	250	5.150	%	February 2017	February 2017
Senior notes			180	6.875		September 2017	March 2018
First mortgage bonds			100	3.210		October 2017	October 2017
Total Consumers		$	530
Total CMS Energy		$	730

1Outstanding borrowings bear interest at an annual interest rate of LIBOR plus 0.68 percent (2.28 percent at December 31, 2017). CMS Energy used these proceeds to retire $200 million of the 8.75 percent senior notes due June 2019.

2CMS Energy retired this debt at a premium and recorded a loss on extinguishment of $18 million in other expense on its consolidated statements of income.

Debt Maturities

In Millions
	2018			2019			2020			2021			2022
CMS Energy, including Consumers
Long-term debt		$	1,081		$	1,428		$	905		$	178		$	1,039
Consumers
Long-term debt		$	343		$	876		$	426		$	27		$	653

Revolving Credit Facilities

In Millions
	Amount of			Amount			Letters of Credit			Amount
Expiration Date	Facility			Borrowed			Outstanding			Available
CMS Energy, parent only
May 27, 20221,2		$	550		$	-		$	6		$	544
Consumers3
May 27, 20222		$	650		$	-		$	7		$	643
November 23, 20194			250			-			20			230
September 9, 20195			30			-			30			-

1During the year ended December 31, 2017, CMS Energy’s average borrowings totaled $21 million with a weighted-average interest rate of 2.02 percent. Obligations under this facility are secured by Consumers common stock.

2In May 2017, the expiration date of this revolving credit agreement was extended from May 2021 to May 2022.

3Obligations under these facilities are secured by first mortgage bonds of Consumers.

4In November 2017, the expiration date of this revolving credit agreement was extended from November 2018 to November 2019.

5In June 2017, the expiration date of this letter of credit reimbursement agreement was extended from May 2018 to September 2019.

Consumers Energy Company [Member]

Summary Of Long-Term Debt Outstanding

In Millions
	Interest Rate  (%)		Maturity	2017			2016
Consumers
First mortgage bonds1	5.150		2017		$	-		$	250
	3.210		2017			-			100
	5.650		2018			250			250
	6.125		2019			350			350
	6.700		2019			500			500
	5.650		2020			300			300
	3.770		2020			100			100
	5.300		2022			250			250
	2.850		2022			375			375
	3.375		2023			325			325
	3.190		2024			52			52
	3.125		2024			250			250
	3.390		2027			35			35
	3.180		2032			100			-
	5.800		2035			175			175
	3.520		2037			335			-
	6.170		2040			50			50
	4.970		2040			50			50
	4.310		2042			263			263
	3.950		2043			425			425
	4.100		2045			250			250
	3.250		2046			450			450
	3.950		2047			350			-
	3.860		2052			50			-
	4.350		2064			250			250
Total first mortgage bonds					$	5,535		$	5,050
Securitization bonds	2.913	2	2020-2029	3		302			328
Senior notes	6.875		2018			-			180
Tax-exempt pollution control revenue bonds	various		2018-2035			103			103
Total principal amount outstanding					$	5,940		$	5,661
Current amounts						(343)			(375)
Net unamortized discounts						(8)			(8)
Unamortized issuance costs						(28)			(25)
Total long-term debt					$	5,561		$	5,253

1The weighted-average interest rate for Consumers’ first mortgage bonds was 4.44 percent at December 31, 2017 and 4.57 percent at December 31, 2016.

2The weighted-average interest rate for Consumers’ securitization bonds issued through its subsidiary Consumers 2014 Securitization Funding was 2.91 percent at December 31, 2017 and 2.79 percent at December 31, 2016.

3Principal and interest payments are made semiannually.

Major Long-Term Debt Transactions

	Principal					Issue/Retirement
	(In Millions)			Interest Rate		Date	Maturity Date
Debt issuances
CMS Energy, parent only
Senior notes		$	350	3.450	%	February 2017	August 2027
Term loan facility1			225	variable		December 2017	December 2018
Total CMS Energy, parent only		$	575
Consumers
First mortgage bonds		$	350	3.950	%	February 2017	July 2047
First mortgage bonds			40	3.180		September 2017	September 2032
First mortgage bonds			125	3.520		September 2017	September 2037
First mortgage bonds			20	3.860		September 2017	September 2052
First mortgage bonds			60	3.180		November 2017	November 2032
First mortgage bonds			210	3.520		November 2017	November 2037
First mortgage bonds			30	3.860		November 2017	November 2052
Total Consumers		$	835
Total CMS Energy		$	1,410
Debt retirements
CMS Energy, parent only
Senior notes2		$	200	8.750	%	December 2017	June 2019
Total CMS Energy, parent only		$	200
Consumers
First mortgage bonds		$	250	5.150	%	February 2017	February 2017
Senior notes			180	6.875		September 2017	March 2018
First mortgage bonds			100	3.210		October 2017	October 2017
Total Consumers		$	530
Total CMS Energy		$	730

1Outstanding borrowings bear interest at an annual interest rate of LIBOR plus 0.68 percent (2.28 percent at December 31, 2017). CMS Energy used these proceeds to retire $200 million of the 8.75 percent senior notes due June 2019.

2CMS Energy retired this debt at a premium and recorded a loss on extinguishment of $18 million in other expense on its consolidated statements of income.

Debt Maturities

In Millions
	2018			2019			2020			2021			2022
CMS Energy, including Consumers
Long-term debt		$	1,081		$	1,428		$	905		$	178		$	1,039
Consumers
Long-term debt		$	343		$	876		$	426		$	27		$	653

Revolving Credit Facilities

In Millions
	Amount of			Amount			Letters of Credit			Amount
Expiration Date	Facility			Borrowed			Outstanding			Available
CMS Energy, parent only
May 27, 20221,2		$	550		$	-		$	6		$	544
Consumers3
May 27, 20222		$	650		$	-		$	7		$	643
November 23, 20194			250			-			20			230
September 9, 20195			30			-			30			-

1During the year ended December 31, 2017, CMS Energy’s average borrowings totaled $21 million with a weighted-average interest rate of 2.02 percent. Obligations under this facility are secured by Consumers common stock.

2In May 2017, the expiration date of this revolving credit agreement was extended from May 2021 to May 2022.

3Obligations under these facilities are secured by first mortgage bonds of Consumers.

4In November 2017, the expiration date of this revolving credit agreement was extended from November 2018 to November 2019.

5In June 2017, the expiration date of this letter of credit reimbursement agreement was extended from May 2018 to September 2019.

Preferred Stock

				Optional			Number of	Balance
				Redemption			Shares	Outstanding
	Series			Price			Outstanding	(In Millions)
December 31								2017			2016
Cumulative, $100 par value, authorized 7,500,000 shares, with no mandatory    redemption		$	4.50		$	110.00	373,148		$	37		$	37