Goodwill

The changes in the carrying amount of goodwill by segment were as follows:



(in millions)	Defense and Intelligence			Civilian and Health Care		Total
Balance as of March 31, 2018	$	977		$	1,045	$	2,022
Additions	1,074			83		1,157
Balance as of March 31, 2019	2,051			1,128		3,179
Additions	22			94		116
Impairment charges	(624		)	—		(624		)
Balance as of March 31, 2020	$	1,449		$	1,222	$	2,671

Goodwill is stated net of accumulated impairment losses of $624 million at March 31, 2020. The additions to goodwill were primarily due to the Mergers described in Note 2 – “Acquisitions.”

The U.S. Navy announced on February 5, 2020 that Perspecta was not awarded the NGEN-R SMIT contract, the re-compete of the NGEN contract currently held by the Company. The NGEN contract was scheduled to expire on September 30, 2020, but three one-month options were exercised by the U.S. Navy, extending the contract through December 31, 2020. In connection with the April 1, 2017 merger of CSC with HPES to form DXC, the reporting unit with the NGEN contract was allocated $624 million of goodwill. As a result of the U.S. Navy’s decision not to award the NGEN-R SMIT contract to us, we tested this goodwill for impairment in the fourth quarter of fiscal year 2020 and deemed it fully impaired.