10. Line of Credit, Long-Term Debt and Capital Lease Obligations:

The Company’s Credit Agreement provides for a $2.0 billion unsecured revolving credit facility and includes a $37.5 million sub-facility for the issuance of letters of credit. In November 2018, the Company amended and restated its Credit Agreement to make certain technical, conforming and other changes. The Credit Agreement matures on October 31, 2022 and is guaranteed by substantially all of the Company’s subsidiaries and affiliated professional associations and corporations. At the Company’s option, borrowings under the Credit Agreement will bear interest at (i) the alternate base rate (defined as the higher of (a) the prime rate, (b) the Federal Funds Rate plus 1/2 of 1.00% and (c) LIBOR for an interest period of one month plus 1.00%) plus an applicable margin rate ranging from 0.125% to 0.750% based on the Company’s consolidated leverage ratio or (ii) the LIBOR rate plus an applicable margin rate ranging from 1.125% to 1.750% based on the Company’s consolidated leverage ratio. The Credit Agreement also calls for other customary fees and charges, including an unused commitment fee ranging from 0.150% to 0.300% of the unused lending commitments, based on the Company’s consolidated leverage ratio.

The Credit Agreement contains customary covenants and restrictions, including covenants that require the Company to maintain a minimum interest charge ratio, not to exceed a specified consolidated leverage ratio and to comply with laws, and restrictions on the ability of the Company to pay dividends and make certain other distributions, as specified therein. Failure to comply with these covenants would constitute an event of default under the Credit Agreement, notwithstanding the ability of the Company to meet its debt service obligations. The Credit Agreement also includes various customary remedies for the lenders following an event of default, including the acceleration of repayment of outstanding amounts under the Credit Agreement.

In December 2015, the Company completed a private offering of $750.0 million aggregate principal amount of 2023 Notes. In November 2018, the Company completed a private offering of $500.0 million aggregate principal amount of 2027 Notes. The Company’s obligations under the 2023 Notes and the 2027 Notes are guaranteed on an unsecured senior basis by the same subsidiaries and affiliated professional contractors that guarantee the Credit Agreement. Interest on the 2023 Notes accrues at the rate of 5.25% per annum and is payable semi-annually in arrears on June 1 and December 1. Interest on the 2027 Notes accrues at the rate of 6.25% per annum and is payable semi-annually in arrears on January 15 and July 15, with the initial interest payment due on January 15, 2019.

As of December 31, 2018, the Company may redeem all or a portion of the 2023 Notes, at the redemption prices of 102.625% in 2019, 101.313% in 2020 and 100% in 2021 and thereafter, plus accrued and unpaid interest to the redemption date.

At any time prior to January 15, 2022, the Company may redeem all or a portion of the 2027 Notes at a redemption price equal to 100% of the principal amount of the notes being redeemed plus an applicable redemption premium and accrued and unpaid interest to the redemption date. In addition, at any time prior to January 15, 2022, the Company may redeem up to 35% of the aggregate principal amount of the 2027 Notes at a redemption price of 106.250% of the principal amount thereof, plus accrued and unpaid interest, if any, to the redemption date, using proceeds from one or more equity offerings. On or after January 15, 2022, the Company may redeem all or a portion of the 2027 Notes, at the redemption prices of 104.688% in 2022, 103.125% in 2023, 101.563% in 2024 and 100% in 2025 and thereafter, plus accrued and unpaid interest to the redemption date.

The indenture under which the 2023 Notes and the 2027 Notes are issued, among other things, limits our ability to (1) incur liens and (2) enter into sale and lease-back transactions, and also limits our ability to merge or dispose of all or substantially all of our assets, in all cases, subject to a number of customary exceptions. Although we are not required to make mandatory redemption or sinking fund payments with respect to the 2023 Notes or the 2027 Notes, upon the occurrence of a change in control of MEDNAX, we may be required to repurchase the 2023 Notes or the 2027 Notes at a purchase price equal to 101% of the aggregate principal amount of the 2023 Notes and the 2027 Notes repurchased plus accrued and unpaid interest.

The carrying value of the Company’s long-term debt was $2.0 billion and $1.8 billion at December 31, 2018 and 2017, respectively, and consisted of the following (in thousands):


	December 31, 2018
	Principal		Unamortized Debt Issuance Costs			Total
Senior Notes	$	1,250,000	$	(15,408	)	$	1,234,592
Revolving line of credit		739,500		(4,274	)		735,226

Total	$	1,989,500	$	(19,682	)	$	1,969,818


	December 31, 2017
	Principal		Unamortized Debt Issuance Costs			Total
Senior Notes	$	750,000	$	(9,503	)	$	740,497
Revolving line of credit		1,110,500		(4,864	)		1,105,636

Total	$	1,860,500	$	(14,367	)	$	1,846,133

The Company presents issuance costs related to long-term debt liabilities, other than revolving credit arrangements, as a direct deduction from the carrying value of that long-term debt. The Company has outstanding letters of credit which reduced the amount available under the Credit Agreement by $0.2 million at December 31, 2018. At December 31, 2018, the Company had an available balance on its Credit Agreement of $1.3 billion.

The carrying values of the Company’s variable rate revolving line of credit approximates fair value due to the short-term nature of the interest rates. The estimated fair value of the Company’s 2023 Notes and 2027 Notes were estimated using trading prices as of December 31, 2018 and 2017, respectively, as Level 2 inputs to estimate fair value and are summarized as follows (in thousands):


	December 31,
	2018		2017
2023 Notes	$	736,725	$	763,125
2027 Notes		482,500		—

The Company’s capital lease obligations consist of the following (in thousands):


	December 31,
	2018			2017
Capital lease obligations	$	441		$	1,826
Less: Current portion		(253	)		(1,401	)

Long-term portion	$	188		$	425

The amounts due under the terms of the Company’s capital lease obligations at December 31, 2018 are as follows:


2019	$	253
2020		114
2021		74