CONVERTIBLE SUBORDINATED NOTES

The carrying values of the liability and equity components of our 2.75% convertible subordinated notes due 2021 (the “Convertible Notes”) at December 31, 2019 and March 31, 2020 are reflected on our Consolidated Balance Sheet as follows (in thousands):



	December 31, 2019			March 31, 2020
Current liabilities:
Principal amount	$	6,319		$	6,319
Unamortized discount of liability component	(319		)	(254		)
Convertible Notes issuance costs, net of accumulated amortization of $130 and $136, respectively	(29		)	(23		)
Carrying value of the liability component	$	5,971		$	6,042

Carrying value of the equity component	$	789		$	789

The carrying value of the liability component and the carrying value of the equity component are recorded in Convertible subordinated notes due 2021 and Additional paid-in capital, respectively, on our Consolidated Balance Sheet at December 31, 2019 and March 31, 2020. The balance of our deferred tax liability related to our Convertible Notes was $0.1 million at March 31, 2020.

The fair value of the Convertible Notes, which are Level 2 measurements, was $6.4 million at March 31, 2020. The Convertible Notes are due in March 2021 and bear interest at 2.75% per year, which is payable semi-annually in arrears on March 15 and September 15 of each year.

At March 31, 2020, the adjusted conversion rate of the Convertible Notes is 45.5554 shares of our common stock per $1,000 principal amount of Convertible Notes, equivalent to an adjusted conversion price of $21.95 per share of common stock.

Interest expense on the Convertible Notes included contractual coupon interest expense of $44,000 and $43,000 for the three months ended March 31, 2019 and 2020, respectively. Accretion of the discount on the Convertible Notes was $57,000 and $65,000 for the three months ended March 31, 2019 and 2020, respectively. Amortization of debt issuance costs related to our Convertible Notes was $6,000 for both the three months ended March 31, 2019 and 2020.

The remaining unamortized debt discount and the remaining unamortized debt issuance costs are being amortized using the effective interest method over the remaining term of approximately 11 months of the Convertible Notes. The effective interest rate on the unamortized debt discount for both the three months ended March 31, 2019 and 2020 was 11.4%. The effective interest rate on the debt issuance costs for both three months ended March 31, 2019 and 2020 was 3.2%.