TEP categorizes financial instruments into the three-level hierarchy based on inputs used to determine the fair value. Level 1 inputs are unadjusted quoted prices for identical assets or liabilities in an active market. Level 2 inputs include quoted prices for similar assets or liabilities, quoted prices in non-active markets, and pricing models whose inputs are observable, directly or indirectly. Level 3 inputs are unobservable and supported by little or no market activity.

The following tables present, by level within the fair value hierarchy, TEP’s assets and liabilities accounted for at fair value through net income on a recurring basis classified in their entirety based on the lowest level of input that is significant to the fair value measurement:



	Level 1		Level 2			Level 3		Total
(in millions)	December 31, 2019
Assets
Restricted Cash ⁽¹⁾	$	18	$	—		$	—	$	18
Energy Derivative Contracts, Regulatory Recovery ⁽²⁾	—		3			—		3
Energy Derivative Contracts, No Regulatory Recovery ⁽²⁾	—		3			—		3
Total Assets	18		6			—		24
Liabilities
Energy Derivative Contracts, Regulatory Recovery ⁽²⁾	—		(76		)	—		(76		)
Total Liabilities	—		(76		)	—		(76		)
Total Assets (Liabilities), Net	$	18	$	(70	)	$	—	$	(52	)



(in millions)	December 31, 2018
Assets
Cash Equivalents ⁽¹⁾	$	55	$	—		$	—		$	55
Restricted Cash ⁽¹⁾	15		—			—			15
Energy Derivative Contracts, Regulatory Recovery ⁽²⁾	—		10			—			10
Energy Derivative Contracts, No Regulatory Recovery ⁽²⁾	—		—			2			2
Total Assets	70		10			2			82
Liabilities
Energy Derivative Contracts, Regulatory Recovery ⁽²⁾	—		(35		)	(2		)	(37		)
Total Liabilities	—		(35		)	(2		)	(37		)
Total Assets (Liabilities), Net	$	70	$	(25	)	$	—		$	45

All energy derivative contracts are subject to legally enforceable master netting arrangements to mitigate credit risk. TEP presents derivatives on a gross basis in the balance sheet. The tables below present the potential offset of counterparty netting and cash collateral.



	Gross Amount Recognized in the Balance Sheets			Gross Amount Not Offset in the Balance Sheets						Net Amount
	Gross Amount Recognized in the Balance Sheets			Counterparty Netting of Energy Contracts			Cash Collateral Received/Posted			Net Amount
(in millions)	December 31, 2019
Derivative Assets
Energy Derivative Contracts	$	6		$	4		$	—		$	2
Derivative Liabilities
Energy Derivative Contracts	(76		)	(4		)	(2		)	(70		)



(in millions)	December 31, 2018
Derivative Assets
Energy Derivative Contracts	$	12		$	11		$	—	$	1
Derivative Liabilities
Energy Derivative Contracts	(37		)	(11		)	—		(26		)

TEP enters into various derivative and non-derivative contracts to reduce exposure to energy price risk associated with its natural gas and purchased power requirements. The objectives for entering into such contracts include: (i) creating price stability; (ii) meeting load and reserve requirements; and (iii) reducing exposure to price volatility that may result from delayed recovery under the PPFAC mechanism. In addition, TEP enters into derivative and non-derivative contracts to optimize the system's generation resources by selling power in the wholesale market for the benefit of the Company's retail customers.

The Company primarily applies the market approach for recurring fair value measurements. When TEP has observable inputs for substantially the full term of the asset or liability or uses quoted prices in an inactive market, it categorizes the instrument in Level 2. TEP categorizes derivatives in Level 3 when an aggregate pricing service or published prices that represent a consensus reporting of multiple brokers is used.

For both purchased power and natural gas prices, TEP obtains quotes from brokers, major market participants, exchanges, or industry publications and relies on its own price experience from active transactions in the market. The Company primarily uses one set of quotations each for purchased power and natural gas and then validates those prices using other sources. TEP believes that the market information provided is reflective of market conditions as of the time and date indicated.

Published prices for energy derivative contracts may not be available due to the nature of contract delivery terms such as non-standard time blocks and non-standard delivery points. In these cases, TEP applies adjustments based on historical price curve relationships, transmission costs, and line losses.

The inputs and the Company's assessments of the significance of a particular input to the fair value measurements require judgment and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. TEP reviews the assumptions underlying its price curves monthly.

To mitigate the exposure to volatility in variable interest rates on debt, TEP had an interest rate swap agreement that expired in January 2020. As of December 31, 2019, the total notional amount of the interest rate swap was $6 million. No notional amount remained as of February 12, 2020. The after-tax unrealized gains and losses on cash flow hedge activities were reported in the statement of comprehensive income. The estimated loss expected to be reclassified to earnings within the next twelve months and the realized loss recorded to Interest Expense on the Consolidated Statements of Income are not material to TEP's financial position or results of operations.

TEP enters into energy contracts that are considered derivatives and qualify for regulatory recovery. The realized gains and losses on these energy contracts are recovered through the PPFAC mechanism and the unrealized gains and losses are deferred as a regulatory asset or a regulatory liability. The table below presents the unrealized gains and losses recorded to a regulatory asset or a regulatory liability in the balance sheet:



	Years Ended December 31,
(in millions)	2019			2018			2017
Unrealized Net Loss ⁽¹⁾	$	(45	)	$	(9	)	$	(18	)

TEP enters into certain energy contracts that are considered derivatives but do not qualify for regulatory recovery. The Company records unrealized gains and losses for these contracts in the income statement unless a normal purchase or normal sale election is made. For contracts that meet the trading definition, as defined in the PPFAC plan of administration, TEP must share 10% of any realized gains with retail customers through the PPFAC mechanism. The table below presents amounts recorded in Operating Revenues on the Consolidated Statements of Income:



	Years Ended December 31,
(in millions)	2019		2018		2017
Operating Revenues	$	6	$	5	$	5

As of December 31, 2019, TEP had energy contracts that will settle on various expiration dates through 2029. The following table presents volumes associated with the energy contracts:



	December 31,
	2019	2018
Power Contracts GWh	4,740	1,743
Gas Contracts BBtu	122,779	146,933

As of December 31, 2019, TEP does not have any Level 3 assets and liabilities balances remaining. The following table provides quantitative information regarding significant unobservable inputs in TEP’s Level 3 fair value measurements:

Valuation Approach

Fair Value of

Unobservable Inputs

Range of Unobservable Inputs

Assets

Liabilities

(in millions)

December 31, 2018

Forward Power Contracts

Market approach

)

Market price per MWh

16.80

47.05

Changes in one or more of the unobservable inputs could have a significant impact on the fair value measurement depending on the magnitude of the change and the direction of the change for each input. The impact of changes to fair value, including changes from unobservable inputs, are subject to recovery or refund through the PPFAC mechanism and are reported as a regulatory asset or regulatory liability, or as a component of other comprehensive income (loss), rather than in the income statement.

The following table presents a reconciliation of changes in the fair value of net assets and liabilities classified as Level 3 in the fair value hierarchy and the gains (losses) attributable to the change in unrealized gains (losses) relating to assets (liabilities) still held at the end of the period:



	Years Ended December 31,
(in millions)	2019			2018
Beginning of Period	$	1		$	2
Gains (Losses) Recorded
Regulatory Assets or Liabilities, Derivative Instruments	(12		)	(4		)
Operating Revenues	5			5
Settlements	1			(2		)
Transfers Out of Level 3 ⁽¹⁾	5			—
End of Period	$	—		$	1

Gains (Losses), Assets (Liabilities) Still Held	$	—		$	1

The use of contractual arrangements to manage the risks associated with changes in energy commodity prices creates credit risk exposure resulting from the possibility of non-performance by counterparties pursuant to the terms of their contractual obligations. TEP enters into contracts for the physical delivery of power and natural gas which contain remedies in the event of non-performance by the supply counterparties. In addition, volatile energy prices can create significant credit exposure from energy market receivables and subsequent measurements at fair value.

TEP has contractual agreements for energy procurement and hedging activities that contain certain provisions requiring TEP and its counterparties to post collateral under certain circumstances. These circumstances include: (i) exposures in excess of unsecured credit limits; (ii) credit rating downgrades; or (iii) a failure to meet certain financial ratios. In the event that such credit events were to occur, the Company, or its counterparties, would have to provide certain credit enhancements in the form of cash, LOCs, or other acceptable security to collateralize exposure beyond the allowed amounts.

TEP considers the effect of counterparty credit risk in determining the fair value of derivative instruments that are in a net asset position, after incorporating collateral posted by counterparties, and then allocates the credit risk adjustment to individual contracts. TEP also considers the impact of its credit risk on instruments that are in a net liability position, after considering the collateral posted, and then allocates the credit risk adjustment to the individual contracts.

The value of all derivative instruments in net liability positions under contracts with credit risk-related contingent features, including contracts under the normal purchase normal sale exception, was $100 million as of December 31, 2019, compared with $41 million as of December 31, 2018. As of December 31, 2019, TEP had $2 million of cash posted as collateral to provide credit enhancement which was reflected in Current Assets—Other on the Consolidated Balance Sheets. As of February 12, 2020, there was no collateral posted. If the credit risk contingent features were triggered on December 31, 2019, TEP would have been required to post an additional $98 million of collateral of which $19 million relates to outstanding net payable balances for settled positions.

The fair value of a financial instrument is the market price to sell an asset or transfer a liability at the measurement date. Borrowings under revolving credit facilities approximate fair value due to the short-term nature of these financial instruments. These items have been excluded from the table below.

The use of different estimation methods and/or market assumptions may yield different estimated fair value amounts. The following table includes the net carrying value and estimated fair value of TEP's long-term debt:



		Net Carrying Value				Fair Value
	Fair Value Hierarchy	December 31,
(in millions)	Fair Value Hierarchy	2019		2018		2019		2018
Liabilities
Long-Term Debt, including Current Maturities	Level 2	$	1,602	$	1,615	$	1,755	$	1,672