Derivatives and Other Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2025

Fair Value Disclosures [Abstract]

Schedule of Detail for Level 1 and 3 Derivatives

The following tables present the detail for Level 1 and 3 derivatives (see additional Level 3 information in further tables below):

	March 31, 2025				December 31, 2024
	Assets		Liabilities		Assets		Liabilities
Level 1 derivative instruments	$	19	$	12	$	1	$	20
Level 3 derivative instruments		30		1,096		24		1,079
Total	$	49	$	1,108	$	25	$	1,099
Less: Current		38		258		25		263
Noncurrent	$	11	$	850	$	—	$	836

	2025						2024
First quarter ended March 31,	Unrealized gain (loss) recognized in Other comprehensive income (loss)			Realized loss reclassified from Accumulated other comprehensive loss to earnings			Unrealized (loss) gain recognized in Other comprehensive income (loss)			Realized gain (loss) reclassified from Accumulated other comprehensive loss to earnings
Level 1 derivative instruments	$	24		$	(2	)	$	(3	)	$	4
Level 3 derivative instruments		(109	)		(93	)		120			(57	)
Total	$	(85	)	$	(95	)	$	117		$	(53	)

Schedule of Outstanding Quantities of Derivative Instruments

The following table presents the outstanding quantities of derivative instruments classified as Level 1:

	Classification	March 31, 2025		March 31, 2024
Aluminum (in kmt)	Commodity buy forwards		173		101
Aluminum (in kmt)	Commodity sell forwards		458		44
Foreign currency (in millions of euro)	Foreign exchange buy forwards		163		79
Foreign currency (in millions of euro)	Foreign exchange sell forwards		11		17
Foreign currency (in millions of euro) (undesignated)	Foreign exchange buy forwards		852		—
Foreign currency (in millions of Norwegian krone)	Foreign exchange buy forwards		20		102
Foreign currency (in millions of Brazilian real)	Foreign exchange buy forwards		160		450
Foreign currency (in millions of Australian dollars)	Foreign exchange buy forwards		41		—
Foreign currency (in millions of Canadian dollar)	Foreign exchange buy forwards		—		26
Natural gas (in millions of megawatt hours)	Commodity buy forwards		2		—

Schedule of Quantitative Information for Level 3 Derivative Contracts

The following table presents quantitative information related to the significant unobservable inputs described above for Level 3 derivative instruments (megawatt hours in MWh):

	March 31, 2025		Unobservable Input	Unobservable Input Range
Asset Derivatives
Financial contract (undesignated)	$	30	Interrelationship of forward energy price, LME forward price and the Consumer Price Index	Electricity (per MWh)	2025: $31.92 2025: $60.48
				LME (per mt)	2025: $2,516
					2025: $2,547
Power contract		—	MWh of energy needed to produce the forecasted mt of aluminum	LME (per mt)	2025: $2,516 2025: $2,530
				Midwest premium (per pound)	2025: $0.5200 2025: $0.5200
				Electricity	Rate of 2 million MWh per year
Total Asset Derivatives	$	30
Liability Derivatives
Power contract	$	135	MWh of energy needed to produce the forecasted mt of aluminum	LME (per mt)	2025: $2,516 2027: $2,624
				Electricity	Rate of 4 million MWh per year
Power contracts		958	MWh of energy needed to produce the forecasted mt of aluminum	LME (per mt)	2025: $2,516 2029: $2,701 2036: $2,888
				Midwest premium (per pound)	2025: $0.5200 2029: $0.5200 2036: $0.5200
				Electricity	Rate of 18 million MWh per year
Power contract (undesignated)		3	Estimated spread between the 30-year debt yield of Alcoa and the counterparty	Credit spread	1.35%: 30-year debt yield spread 6.70%: Alcoa (estimated) 5.35%: counterparty
Total Liability Derivatives	$	1,096

Schedule of Fair Values of Level 3 Derivative Instruments Recorded as Assets and Liabilities

The fair values of Level 3 derivative instruments recorded in the accompanying Consolidated Balance Sheet were as follows:

Asset Derivatives	March 31, 2025		December 31, 2024
Derivatives not designated as hedging instruments:
Current—financial contract	$	30	$	24
Total derivatives not designated as hedging instruments	$	30	$	24
Total Asset Derivatives	$	30	$	24
Liability Derivatives
Derivatives designated as hedging instruments:
Current—power contracts	$	249	$	251
Noncurrent—power contracts		844		826
Total derivatives designated as hedging instruments	$	1,093	$	1,077
Derivatives not designated as hedging instruments:
Current—embedded credit derivative	$	1	$	1
Noncurrent—embedded credit derivative		2		1
Total derivatives not designated as hedging instruments	$	3	$	2
Total Liability Derivatives	$	1,096	$	1,079

Schedule of Reconciliation of Activity for Derivative Contracts

The following tables present the reconciliation of activity for Level 3 derivative instruments:

	Assets
First quarter ended March 31, 2025	Financial contracts
January 1, 2025	$	24
Total gains or losses included in:
Other income, net (unrealized/realized)		8
Settlements and other		(2	)
March 31, 2025	$	30
Change in unrealized gains or losses included in earnings    for derivative instruments held at March 31, 2025:
Other income, net	$	8

	Liabilities
First quarter ended March 31, 2025	Power contracts			Embedded credit derivative
January 1, 2025	$	1,077		$	2
Total gains or losses included in:
Sales (realized)		(93	)		—
Other expenses, net (unrealized/realized)		—			1
Other comprehensive loss (unrealized)		109			—
March 31, 2025	$	1,093		$	3
Change in unrealized gains or losses included in earnings    for derivative instruments held at March 31, 2025:
Other expenses, net	$	—		$	1

Schedule of Carrying Values and Fair Values of Other Financial Instruments

The carrying values and fair values of Alcoa Corporation’s other financial instruments were as follows:

	March 31, 2025				December 31, 2024
	Carrying value		Fair value		Carrying value		Fair value
Cash and cash equivalents	$	1,202	$	1,202	$	1,138	$	1,138
Restricted cash		88		88		96		96
Short-term borrowings		45		45		50		50
Long-term debt due within one year		75		75		75		75
Long-term debt, less amount due within one year		2,573		2,594		2,470		2,499