Debt consists of the following ($ in millions):



	December 31, 2018			December 31, 2017
$1,400 million 5.625% Senior notes, due February 15, 2021	$	1,400		$	1,400
$1,000 million 4.75% Senior notes, due May 15, 2022	1,005			1,006
$1,000 million 6.125% Senior notes, due February 15, 2024	1,000			1,000
$1,200 million 4.75% Senior notes, due January 15, 2025	1,200			1,200
$1,800 million 5.375% Senior notes, due June 1, 2026	1,800			—
Fair value of interest rate swap agreements	(95		)	(71		)
Total senior notes	6,310			4,535
Revolving credit agreement	284			150
Mortgage notes payable	57			61
Construction loan payable	63			—
Capital leases and other	47			18
Debt issuance costs	(75		)	(65		)
Total debt	6,686			4,699
Less current portion	(38		)	(4		)
Long-term debt	$	6,648		$	4,695

Senior Notes

In May 2018, a wholly-owned unrestricted subsidiary of the Company (Escrow Issuer) issued $1,800 million in aggregate principal amount of 5.375% senior notes due 2026 at par. In connection with the closing of the Fidelis Care acquisition, the Escrow Issuer merged with and into the Company and the Company assumed the obligations of the Escrow Issuer under the 5.375% senior notes due 2026. The Company used the net proceeds of the offering to finance a portion of the cash consideration for the Fidelis Care acquisition, which closed in July 2018, to pay related fees and expenses, and for general corporate purposes, including the repayment of outstanding indebtedness.

The indentures governing the senior notes listed in the table above contain restrictive covenants of Centene Corporation. At December 31, 2018, the Company was in compliance with all covenants.

Interest Rate Swaps

The Company uses interest rate swap agreements to convert a portion of its interest rate exposure from fixed rates to floating rates to more closely align interest expense with interest income received on its cash equivalent and variable rate investment balances. The following is a summary of the notional amounts of the Company's interest rate swap agreements as of December 31, 2018 and 2017 ($ in millions):



Expiration Date	Notional Amount
February 15, 2021	$	600
May 15, 2022	500
February 15, 2024	1,000
January 15, 2025	600
Total	$	2,700

The fair value of the swap agreements shown above are recorded in other long-term liabilities in the Consolidated Balance Sheets. Under the swap agreements, the Company receives a fixed rate of interest and pays an average variable rate of either the one or three month LIBOR plus 3.61% adjusted monthly or quarterly, based on the terms of the individual swap agreements. At December 31, 2018, the weighted average rate was 6.19%.

The swap agreements are formally designated and qualify as fair value hedges. Gains and losses due to changes in fair value of the interest rate swap agreements completely offset changes in the fair value of the hedged portion of the underlying debt. Therefore, no gain or loss has been recognized due to hedge ineffectiveness. Offsetting changes in fair value of both the interest rate swaps and the hedged portion of the underlying debt both were recognized in interest expense in the Consolidated Statements of Operations. The Company does not hold or issue any derivative instrument for trading or speculative purposes.

The fair value of the Swap Agreements excludes accrued interest and takes into consideration current interest rates and current likelihood of the swap counterparties' compliance with its contractual obligations.

Revolving Credit Agreement

The Company has an unsecured $1,500 million revolving credit facility. The agreement has a maturity date of December 14, 2022. Borrowings under the agreement bear interest based upon LIBOR, EURIBOR rates, the Federal Funds Rate or the Prime Rate. As of December 31, 2018, the Company had $284 million of borrowings outstanding under the agreement with a weighted average interest rate of 4.42%, and the Company was in compliance with all covenants.

The revolving credit facility contains non-financial and financial covenants, including requirements of minimum fixed charge coverage ratios and maximum debt-to-EBITDA ratios. The Company is required to not exceed a maximum debt-to-EBITDA ratio of 3.5 to 1.0. As of December 31, 2018, there were no limitations on the availability under the revolving credit agreement as a result of the debt-to-EBITDA ratio.

Mortgage Notes Payable

The Company has a non-recourse mortgage note of $57 million at December 31, 2018 collateralized by its corporate headquarters building. The mortgage note is due January 1, 2021 and bears a 5.14% interest rate. The collateralized property had a net book value of $162 million at December 31, 2018.

Construction Loan

The Company has a $200 million non-recourse construction loan to fund the expansion of the Company's corporate headquarters. The loan bears interest based on the one month LIBOR plus 2.70% and matures in April 2021 with an optional one-year extension. The agreement contains financial and non-financial covenants aligning with the Company's revolving credit agreement. The Company has guaranteed completion of the construction project associated with the loan. As of December 31, 2018, the Company had $63 million in borrowings outstanding under the loan.

Letters of Credit & Surety Bonds

The Company had outstanding letters of credit of $56 million as of December 31, 2018, which were not part of the revolving credit facility. The Company also had letters of credit for $27 million (valued at December 31, 2018 conversion rate), or €24 million, representing its proportional share of the letters of credit issued to support Ribera Salud's outstanding debt, which are a part of the revolving credit facility. Collectively, the letters of credit bore interest at 0.99% as of December 31, 2018. The Company had outstanding surety bonds of $496 million as of December 31, 2018.

Aggregate maturities for the Company's debt are as follows ($ in millions):



2019	$	38
2020	4
2021	1,514
2022	1,293
2023	—
Thereafter	4,002
Total	$	6,851

The fair value of outstanding debt was approximately $6,619 million and $4,751 million at December 31, 2018 and 2017, respectively.