	December 31, 2018		March 31, 2018
Total debt	$	120,000	$	84,000
Less current portion		—		—
Long-term debt	$	120,000	$	84,000
Deferred debt costs and royalty liability, net of amortization		44		1,063
	$	120,044	$	85,063

The Company’s debt at December 31, 2018 comprises the Secured Notes. On October 14, 2016, the Company completed the private placement of up to $120 million aggregate principal amount of the Secured Notes and entered into an indenture governing the Secured Notes with the guarantors party thereto and U.S. Bank National Association, a national banking association, as trustee and collateral agent. The Company issued $84 million aggregate principal amount of the Secured Notes on October 14, 2016 and an additional $36 million aggregate principal amount of the Secured Notes on June 29, 2018. On December 18, 2018, the Company also completed certain amendments to the indenture governing the Secured Notes. The amendments included an increase to the aggregate principal amount of Secured Notes that can be issued under the indenture from $120.0 million to up to $145.0 million following the European CE Marking of the Company’s initial MosaiQ IH Microarray. Furthermore, on January 15, 2019 the Company entered into purchase agreements pursuant to which the Company agreed to issue and certain purchasers agreed to purchase the additional $25 million of the Secured Notes, subject to the European CE Marking of the Company’s initial MosaiQ IH Microarray occurring on or before April 30, 2019 and certain other customary closing conditions (the "CE Marking Notes").

Furthermore, the obligations of the Company under the indenture and the Secured Notes are unconditionally guaranteed on a secured basis by the guarantors, which include all the Company’s subsidiaries, and the indenture governing the Secured Notes contains customary events of default. The Company and its subsidiaries must also comply with certain customary affirmative and negative covenants, including a requirement to maintain six-months of interest in a cash reserve account maintained with the collateral agent. Upon the occurrence of a Change of Control, subject to certain conditions, or certain Asset Sales (each, as defined in the indenture), holders of the Secured Notes may require the Company to repurchase for cash all or part of their Secured Notes at a repurchase price equal to 101% or 100%, respectively, of the principal amount of the Secured Notes to be repurchased, plus accrued and unpaid interest to the date of repurchase.

The Company paid $7.2 million of the total proceeds of the two issuances into the cash reserve account maintained with the collateral agent under the terms of the indenture, $2.2 million of which related to the second issuance on June 29, 2018.

Interest on the Secured Notes accrues at a rate of 12% per annum and is payable semi-annually on April 15 and October 15 of each year commencing on April 15, 2017. Commencing on April 15, 2021, the Company will also pay an installment of principal of the Secured Notes on each April 15 and October 15 until April 15, 2024 pursuant to a fixed amortization schedule.

In connection with the two prior issuances of the Secured Notes as well as the amendment of the related indenture, the Company has entered into royalty rights agreements, pursuant to which the Company has agreed to pay 3.0% of the aggregate net sales of MosaiQ instruments and consumables made in the donor testing market in the United States and the European Union. Further, pursuant to the purchase agreements that the Company entered into on January 15, 2019, the Company has also agreed to enter into royalty rights agreements at the closing of the CE Marking Notes (if any), pursuant to which the Company will issue the right to receive in the aggregate an additional 0.4% of such net sales. The royalties will be payable beginning on the date that the Company or its affiliates makes its first sale of MosaiQ consumables in the donor testing market in the European Union or the United States and will end on the last day of the calendar quarter in which the eighth anniversary of the first sale date occurs. The existing royalty rights agreements are treated as sales of future revenues that meet the requirements of Accounting Standards Codification Topic 470 “Debt” to be treated as debt. The estimated future cash outflows under the existing royalty rights agreements have been combined with the Secured Notes issuance costs and interest payable to calculate the effective interest rate of the Secured Notes and will be expensed through interest expenses using the effective interest rate method over the term of the Secured Notes and such royalty rights agreements. Estimating the future cash outflows under the existing royalty rights agreements requires the Company to make certain estimates and assumptions about future sales of MosaiQ products. These estimates of the magnitude and timing of MosaiQ sales are subject to significant variability due to the current status of development of MosaiQproducts, and thus are subject to significant uncertainty. Therefore, the estimates are likely to change as the Company gains experience of marketing MosaiQ, which may result in future adjustments to the accretion of the interest expense and amortized cost based carrying value of the Secured Notes.

Within 1 year	$	—
Between 1 and 2 years		—
Between 2 and 3 years		20,000
Between 3 and 4 years		35,000
Between 4 and 5 years		40,000
After 5 years		25,000
Total debt	$	120,000