(6) Intangible assets and goodwill

Intangible assets as of March 31, 2021 are summarized as follows:


			Accumulated		Useful Life
	Cost		Amortization	Net	(in years)
Customer relationships	$	11,800	(1,971)	9,829	15
Developed technology	$	8,300	(1,733)	6,567	12
Licenses	$	63	(22)	41	15
Trade names and trademarks	$	6,300	(1,315)	4,985	12
Capitalized software	$	659	(33)	626	5
Non-compete agreements	$	300	(188)	112	4
Total intangible assets	$	27,422	(5,262)	22,160

Intangible assets as of December 31, 2020 are summarized as follows:


			Accumulated		Useful Life
	Cost		Amortization	Net	(in years)
Customer relationships	$	11,800	(1,774)	10,026	15
Developed technology	$	8,300	(1,560)	6,740	12
Licenses	$	63	(20)	43	15
Trade names and trademarks	$	6,300	(1,184)	5,116	12
Capitalized software	$	659	—	659	5
Non-compete agreements	$	300	(170)	130	4
Total intangible assets	$	27,422	(4,708)	22,714

Total amortization expense was $554 and $520 for the three months ended March 31, 2021 and 2020, respectively.

In November 2015, the Company entered into a license agreement with Stanford University (“Stanford”), pursuant to which Stanford granted the Company an exclusive, worldwide, sublicensable license under certain patent rights to make, use, import and commercialize products for diagnostic, industrial and research and development purposes. In accordance with the agreement, the Company capitalized non-refundable royalties paid to Stanford totaling $63, subject to straight-line amortization over a period of 15 years, or the term of the related agreement.

As of March 31, 2021, the amortization expense related to identifiable intangible assets in future periods is expected to be as follows:


2021 remaining		1,661
2022		2,195
2023		2,140
2024		2,140
2025		2,139
Thereafter		11,885
Total	$	22,160

As of March 31, 2021 and December 31, 2020, the goodwill balance is $18,262.