

	September 30, 2019
	Gross Amount		Accumulated Amortization			Net Amount
Core and developed technology	$	7,347.4	$	(1,526.2	)	$	5,821.2
Customer-related	917.1		(616.1		)	301.0
In-process research and development	9.6		—			9.6
Distribution rights and other	84.6		(29.1		)	55.5
Total	$	8,358.7	$	(2,171.4	)	$	6,187.3



	March 31, 2019
	Gross Amount		Accumulated Amortization			Net Amount
Core and developed technology	$	7,339.2	$	(1,102.2	)	$	6,237.0
Customer-related	917.1		(544.0		)	373.1
In-process research and development	7.7		—			7.7
Distribution rights and other	81.4		(13.6		)	67.8
Total	$	8,345.4	$	(1,659.8	)	$	6,685.6

The following is an expected amortization schedule for the intangible assets for remainder of fiscal 2020 through fiscal 2024, absent any future acquisitions or impairment charges (in millions):



Fiscal Year Ending March 31,		Projected Amortization Expense
2020		$516.1
2021		$970.1
2022		$894.9
2023		$682.7
2024		$616.0

The Company amortizes intangible assets over their expected useful lives, which range between 1 and 15 years. Amortization expense attributed to intangible assets are assigned to cost of sales and operating expenses as follows (in millions):



	Three Months Ended September 30,				Six Months Ended September 30,
	2019		2018		2019		2018
Amortization expense charged to cost of sales	$	2.4	$	2.1	$	4.6	$	3.1
Amortization expense charged to operating expense	255.7		171.7		514.4		305.5
Total amortization expense	$	258.1	$	173.8	$	519.0	$	308.6

The Company recognized impairment charges of $0.5 million in the six months ended September 30, 2019, compared to $1.2 million and $3.1 million in the three and six months ended September 30, 2018, respectively. There were no impairment charges in the three months ended September 30, 2019.

Goodwill activity for the six months ended September 30, 2019 was as follows (amounts in millions):



	Semiconductor Products Reporting Unit		Technology Licensing Reporting Unit
Balance at March 31, 2019	$	6,644.7	$	19.2
Additions	0.7		—
Balance at September 30, 2019	$	6,645.4	$	19.2

At March 31, 2019, the Company applied a qualitative goodwill impairment test to its two reporting units, concluding it was not more likely than not that goodwill was impaired. Through September 30, 2019, the Company has never recorded an impairment charge against its goodwill balance.