The following table summarizes the Company’s total outstanding balance on its Senior Secured Notes net of unamortized discount and deferred financing costs, and Senior Unsecured Notes net of unamortized deferred financing costs, as of March 31, 2022, and December 31, 2021:

The Company’s Credit Agreement, which is scheduled to mature on September 28, 2023, provides for a senior secured revolving credit facility with a maximum loan amount of $2.5 billion. As of March 31, 2022, the borrowing base and aggregate lender commitments under the Credit Agreement were $1.1 billion. Subsequent to March 31, 2022, the semi-annual borrowing base redetermination was completed, which reaffirmed both the Company’s borrowing base and aggregate lender commitments at $1.1 billion. The next borrowing base redetermination date is scheduled for October 1, 2022.

Interest and commitment fees associated with the revolving credit facility are accrued based on a borrowing base utilization grid set forth in the Credit Agreement as presented in Note 5 - Long-Term Debt in the 2021 Form 10-K. At the Company’s election, borrowings under the Credit Agreement may be in the form of Eurodollar, Alternate Base Rate (“ABR”), or Swingline loans. Eurodollar loans accrue interest at the London Interbank Offered Rate (“LIBOR”), plus the applicable margin from the utilization grid, and ABR and Swingline loans accrue interest at a market-based floating rate, plus the applicable margin from the utilization grid. Commitment fees

are accrued on the unused portion of the aggregate lender commitment amount at rates from the utilization grid and are included in the interest expense line item on the accompanying statements of operations.

LIBOR was discontinued as a global reference rate for new loans and contracts after December 31, 2021. The Credit Agreement specifies that if LIBOR is no longer a widely used benchmark rate, or if it is no longer used for determining interest rates for loans in the United States, a replacement interest rate that fairly reflects the cost to the lenders of funding loans shall be established by the Administrative Agent, as defined in the Credit Agreement, in consultation with the Company. In advance of the maturity date of the Company’s existing Credit Agreement, the Company expects to enter into a new credit agreement in 2022 that will, in addition to other negotiated terms, conditions, agreements, and other provisions, specify a new interest rate for Eurodollar loans. The Company does not expect to incur borrowings in the form of Eurodollar loans prior to that time.

The following table presents the outstanding balance, total amount of letters of credit outstanding, and available borrowing capacity under the Credit Agreement as of April 20, 2022, March 31, 2022, and December 31, 2021:


	As of April 20, 2022		As of March 31, 2022		As of December 31, 2021

	(in thousands)
Revolving credit facility (1)	$	—	$	—	$	—
Letters of credit (2)	6,000		6,000		2,500
Available borrowing capacity	1,094,000		1,094,000		1,097,500
Total aggregate lender commitment amount	$	1,100,000	$	1,100,000	$	1,100,000

(1) Unamortized deferred financing costs attributable to the revolving credit facility are presented as a component of the other noncurrent assets line item on the accompanying balance sheets and totaled $2.3 million and $2.7 million as of March 31, 2022, and December 31, 2021, respectively. These costs are being amortized over the term of the revolving credit facility on a straight-line basis.

Senior Secured Notes, net of unamortized discount and deferred financing costs, included within the Senior Notes, net line item on the accompanying balance sheets as of March 31, 2022, and December 31, 2021, consist of the 10.0% Senior Secured Notes due 2025 (“2025 Senior Secured Notes” or “Senior Secured Notes”):


	As of March 31, 2022		As of December 31, 2021
	(in thousands)

Principal amount of 10.0% Senior Secured Notes due 2025	$	446,675	$	446,675
Unamortized debt discount	28,135		30,236
Unamortized deferred financing costs	8,015		8,727
10.0% Senior Secured Notes due 2025, net of unamortized debt discount and deferred financing costs	$	410,525	$	407,712

The 2025 Senior Secured Notes are senior obligations of the Company, secured on a second-priority basis, ranking junior to the Company’s obligations under the Credit Agreement. The 2025 Senior Secured Notes rank senior in right of payment with all of the Company’s existing and any future unsecured senior or subordinated debt.

The Company may redeem some or all of its 2025 Senior Secured Notes prior to their maturity at redemption prices based on a premium, plus accrued and unpaid interest, as described in the indenture governing the 2025 Senior Secured Notes.

On April 28, 2022, the Company issued a notice of redemption to the holders of the 2025 Senior Secured Notes notifying such holders that the Company intends to redeem the $446.7 million aggregate principal amount outstanding of its 2025 Senior Secured Notes on June 17, 2022 (“Redemption Date”). In accordance with the terms of the indenture governing the 2025 Senior Secured Notes, the redemption price will be equal to 107.5 percent of the principal amount of the 2025 Senior Secured Notes on the Redemption Date ($1,075 per $1,000 principal amount outstanding), plus accrued and unpaid interest.

Senior Unsecured Notes, net of unamortized deferred financing costs, included within the Senior Notes, net line item on the accompanying balance sheets as of March 31, 2022, and December 31, 2021, consist of the following (collectively referred to as “Senior Unsecured Notes,” and together with the 2025 Senior Secured Notes, “Senior Notes”):


	As of March 31, 2022						As of December 31, 2021
	Principal Amount		Unamortized Deferred Financing Costs		Principal Amount, Net		Principal Amount		Unamortized Deferred Financing Costs		Principal Amount, Net

	(in thousands)
5.0% Senior Notes due 2024	$	—	$	—	$	—	$	104,769	$	403	$	104,366
5.625% Senior Notes due 2025	349,118		2,001		347,117		349,118		2,160		346,958
6.75% Senior Notes due 2026	419,235		3,095		416,140		419,235		3,270		415,965
6.625% Senior Notes due 2027	416,791		3,755		413,036		416,791		3,949		412,842
6.5% Senior Notes due 2028	400,000		6,426		393,574		400,000		6,679		393,321
Total	$	1,585,144	$	15,277	$	1,569,867	$	1,689,913	$	16,461	$	1,673,452

The Senior Unsecured Notes are unsecured senior obligations and rank equal in right of payment with all of the Company’s existing and any future unsecured senior debt and are senior in right of payment to any future subordinated debt. The Company may redeem some or all of its Senior Unsecured Notes prior to their maturity at redemption prices based on a premium, plus accrued and unpaid interest as described in the indentures governing the Senior Unsecured Notes.

On February 14, 2022, the Company redeemed all of the $104.8 million of aggregate principal amount outstanding of its 5.0% Senior Notes due 2024 (“2024 Senior Notes”), with cash on hand, pursuant to the terms of the indenture governing the 2024 Senior Notes which provided for a redemption price equal to 100 percent of the principal amount of the 2024 Senior Notes on the date of redemption, plus accrued and unpaid interest. Upon redemption, the Company accelerated the amortization of all remaining previously unamortized deferred financing costs. The Company canceled all redeemed 2024 Senior Notes upon settlement.

The Company is subject to certain financial and non-financial covenants under the Credit Agreement and the indentures governing the Senior Notes that, among other terms, limit the Company’s ability to incur additional indebtedness, make restricted payments including dividends, sell assets, create liens that secure debt, enter into transactions with affiliates, merge or consolidate with other entities, and with respect to the Company’s restricted subsidiaries, permit the consensual restriction on the ability of such restricted subsidiaries to pay dividends or indebtedness owing to the Company or to any other restricted subsidiaries. The Company was in compliance with all covenants under the Credit Agreement and the indentures governing the Senior Notes as of March 31, 2022, and through the filing of this report. Please refer to Note 5 - Long-Term Debt in the 2021 Form 10-K for additional detail on the Company’s covenants under the Credit Agreement and indentures governing the Senior Notes.

Capitalized interest costs for the three months ended March 31, 2022, and 2021, totaled $3.0 million and $4.3 million, respectively. The amount of interest the Company capitalizes generally fluctuates based on the amount borrowed, the Company’s capital program, and the timing and amount of costs associated with capital projects that are considered in progress. Capitalized interest costs are included in total costs incurred.