	June 30, 2019
	Principal		Unamortized Discount			Total
Term Loan Credit Agreement	$	40,000	$	(673	)	$	39,327
Less: debt – current		—		—			—
Debt – non-current	$	40,000	$	(673	)	$	39,327

	December 31, 2018
	Principal			Unamortized Discount			Net Carrying Value
Oxford Term Loan Agreement	$	30,000		$	(130	)	$	29,870
Less: debt – current		(7,857	)		—			(7,857	)
Debt – non-current	$	22,143		$	(130	)	$	22,013

Principal, interest and fee payments on Term Loan Credit Agreement at June 30, 2019, are expected to be as follows (in thousands):

Year ended December 31,	Principal		Interest and Fees		Total
2019	$	—	$	1,648	$	1,648
2020		—		3,294		3,294
2021		—		3,285		3,285
2022		15,000		2,873		17,873
2023		20,000		1,300		21,300
2024		5,000		1,269		6,269
Total	$	40,000	$	13,669	$	53,669

Prior to March 29, 2019, the Company maintained a loan and security agreement (the “Oxford Term Loan Agreement”) with Oxford Finance LLC (“Oxford”). The Oxford Term Loan Agreement provided for secured growth capital term loans of up to $40.0 million. The Oxford Term Loan Agreement was available in two tranches. The first tranche of $30.0 million (“2017 Term Loan A”) was drawn by the Company on July 31, 2017, with the proceeds used in part to repay in full all of the outstanding term loans under the previous Term Loan Agreement of $17.6 million and the final payment of the previous Term Loan Agreement of $1.4 million. The availability of the second tranche of $10.0 million (“2017 Term Loan B”) expired on May 14, 2018, and the Company did not elect to draw the 2017 Term Loan B.

On March 29, 2019 (the “Closing Date”), the Company entered into a Credit, Security and Guaranty Agreement (Term Loan) (the “Term Loan Credit Agreement”) with MidCap Financial Trust (“MidCap”) to borrow up to $70 million in three tranches (collectively “2019 Term Loan”), with a maturity date of March 1, 2024. The first advance of $40.0 million (“Tranche 1”) was drawn by the Company on March 29, 2019, with the proceeds used in part to repay in full the outstanding term loans and fees under the Oxford Term Loan Agreement. The Company repaid principal and interest in an aggregate amount equal to approximately $31.2 million and prepayment fees in an aggregate amount equal to approximately $0.6 million, and terminated all obligations under the Oxford Term Loan Agreement. As a result, the Company recorded a loss of $2.1 million on the extinguishment of Oxford term loans in “Interest expense” on the Company's condensed consolidated statements of operations. The second advance of $15.0 million (“Tranche 2”) will be available to the Company from January 1, 2020 through December 31, 2020, subject to the Company’s satisfaction of certain conditions described in the Term Loan Credit Agreement, and (ii) the third advance of $15.0 million (“Tranche 3”) will be available to the Company starting April 1, 2020, through March 31, 2021, subject to the Company’s satisfaction of certain other conditions described in the Term Loan Credit Agreement. The borrowings under the 2019 Term Loan bears interest at the sum of a fixed percentage spread and the greater of (i) 1.8% or (ii) one month LIBOR. The effective interest rate on the Term Loan at June 30, 2019 was approximately 8.10%. All three tranches require interest only payments through April 1, 2022, followed by 24 months of payments with interest and equal payment of principal. The interest only payment period can be extended for 12 months upon achievement of a specified trailing twelve month net revenue target. Prepayments of the 2019 Term Loan under the Term Loan Credit Agreement, in whole or in part, will be subject to early termination fees which decline each year until the fourth anniversary, at which time there is no early termination fee. Upon the final payment, the Company must also pay an exit fee calculated based on a percentage of the aggregate principal amount of all tranches advanced to the Company.

The Company also entered into a Credit, Security and Guaranty Agreement (Revolving Loan) (the “Revolving Loan Credit Agreement”) with MidCap on March 29, 2019, to initially borrow up to $5.0 million. The amount borrowed under the Revolving Loan Credit Agreement can be increased, upon request by the Company by up to an additional $15.0 million, subject to agent and lender approval and the satisfaction of certain conditions. The Revolving Loan Credit Agreement has a maturity date of March 1, 2024. Amounts drawn under the Revolving Loan Credit Agreement bear interest at the sum of a fixed percentage spread and the greater of (i) 1.80% or (ii) one month LIBOR. There are also fractional fees based on the amounts either drawn or undrawn. If the Revolving Loan Credit Agreement is terminated before maturity or the funding obligation is permanently reduced, there are declining fees for the entirety of its term. As of June 30, 2019, the Company had borrowed $4.5 million under the Revolving Loan Credit Agreement, which is included in “Debt – revolving loan” in the Company’s condensed consolidated balance sheets.

The Term Loan Credit Agreement and Revolving Loan Credit Agreement contain certain non-financial covenants, with which the Company was in compliance at June 30, 2019. Additionally, both agreements are secured by most of the Company’s assets, excluding intellectual property.