4.	Goodwill and Intangible Assets

Goodwill

The following summarizes the change in the Company’s goodwill:

	Years Ended March 31,
	2020		2019
Balance at beginning of period	$	3,205,000	$	2,551,000
Goodwill acquired		-		654,000
Balance at end of period	$	3,205,000	$	3,205,000

Intangible Assets

The following is a summary of acquired intangible assets subject to amortization:

		March 31, 2020				March 31, 2019
	Weighted Average Amortization Period	Gross Carrying Value		Accumulated Amortization		Gross Carrying Value		Accumulated Amortization
Intangible assets subject to amortization
Trademarks	9 years	$	827,000	$	435,000	$	1,007,000	$	464,000
Customer relationships	11 years		8,453,000		4,376,000		8,610,000		3,547,000
Order backlog	6 months		-		-		325,000		180,000
Developed technology	5 years		2,817,000		893,000		2,991,000		311,000
Total	9 years	$	12,097,000	$	5,704,000	$	12,933,000	$	4,502,000

During the year ended March 31, 2020, the Company retired $470,000 of fully amortized intangible assets. Amortization expense for acquired intangible assets is as follows:

	Years Ended March 31,
	2020		2019		2018

Amortization expense	$	1,770,000	$	1,194,000	$	710,000

The estimated future amortization expense for acquired intangible assets subject to amortization is as follows:

Year Ending March 31,
2021	$	1,479,000
2022		1,438,000
2023		1,408,000
2024		1,040,000
2025		471,000
Thereafter		557,000
Total	$	6,393,000