NOTE 4. Goodwill and Intangible Assets

Goodwill from acquisitions totaled $580 million during the first three months of 2019, none of which was deductible for tax purposes. The amounts in the “Translation and other” row in the following table primarily relate to changes in foreign currency exchange rates. The goodwill balance by business segment as of December 31, 2018 and March 31, 2019, follow:

Goodwill


(Millions)	Industrial		Safety and Graphics		Health Care		Electronics and Energy		Consumer		Total Company
Balance as of December 31, 2018		2,614		4,325		1,654		1,250		208		10,051
Acquisition activity		—		—		580		—		—		580
Translation and other		(28)		(4)		(11)		(7)		30		(20)
Balance as of March 31, 2019	$	2,586	$	4,321	$	2,223	$	1,243	$	238	$	10,611

Accounting standards require that goodwill be tested for impairment annually and between annual tests in certain circumstances such as a change in reporting units or the testing of recoverability of a significant asset group within a reporting unit. At 3M, reporting units correspond to a division.

As described in Note 17, effective in the first quarter of 2019, the Company changed its business segment reporting in its continuing effort to improve the alignment of its businesses around markets and customers. For any product changes that resulted in reporting unit changes, the Company applied the relative fair value method to determine the impact on goodwill of the associated reporting units. During the first quarter of 2019, the Company completed its assessment of any potential goodwill impairment for reporting units impacted by this new structure and determined that no impairment existed.

Acquired Intangible Assets

The carrying amount and accumulated amortization of acquired finite-lived intangible assets, in addition to the balance of non-amortizable intangible assets, as of March 31, 2019, and December 31, 2018, follow:


	March 31,		December 31,
(Millions)	2019		2018
Customer related intangible assets	$	2,577	$	2,291
Patents		539		542
Other technology-based intangible assets		738		576
Definite-lived tradenames		674		664
Other amortizable intangible assets		125		125
Total gross carrying amount	$	4,653	$	4,198

Accumulated amortization — customer related		(1,034)		(998)
Accumulated amortization — patents		(489)		(487)
Accumulated amortization — other technology-based		(350)		(333)
Accumulated amortization — definite-lived tradenames		(284)		(276)
Accumulated amortization — other		(88)		(88)
Total accumulated amortization	$	(2,245)	$	(2,182)

Total finite-lived intangible assets — net	$	2,408	$	2,016

Non-amortizable intangible assets (primarily tradenames)		639		641
Total intangible assets — net	$	3,047	$	2,657

Certain tradenames acquired by 3M are not amortized because they have been in existence for over 55 years, have a history of leading-market share positions, have been and are intended to be continuously renewed, and the associated products of which are expected to generate cash flows for 3M for an indefinite period of time.

Amortization expense for the three months ended March 31, 2019 and 2018 follows:


	Three months ended
	March 31,
(Millions)	2019		2018
Amortization expense	$	69	$	64

Expected amortization expense for acquired amortizable intangible assets recorded as of March 31, 2019:


	Remainder of												After
(Millions)	2019		2020		2021		2022		2023		2024		2024
Amortization expense	$	215	$	276	$	267	$	252	$	222	$	196	$	980

The preceding expected amortization expense is an estimate. Actual amounts of amortization expense may differ from estimated amounts due to additional intangible asset acquisitions, changes in foreign currency exchange rates, impairment of intangible assets, accelerated amortization of intangible assets and other events. 3M expenses the costs incurred to renew or extend the term of intangible assets.