Intangible Assets, Net

At December 31, 2019, intangible assets, net consisted of the following:



	Useful Life (Years)	Gross January 1, 2019		Additions		Impairment/ Disposal			Gross December 31, 2019		Accumulated Amortization			Net December 31, 2019
Indefinite Lived Assets:
Medicare license	N/A	$	1,994,000	$	—	$	(1,994,000	)	$	—	$	—		$	—
Amortized Intangible Assets:
Network relationships	11-15	109,883,000		34,047,000		—			143,930,000		(60,524,996		)	83,405,004
Management contracts	15	22,832,000		—		—			22,832,000		(9,676,381		)	13,155,619
Member relationships	12	6,696,000		—		—			6,696,000		(2,352,133		)	4,343,867
Patient management platform	5	2,060,000		—		—			2,060,000		(858,329		)	1,201,671
Tradename/trademarks	20	1,011,000		—		—			1,011,000		(105,312		)	905,688
		$	144,476,000	$	34,047,000	$	(1,994,000	)	$	176,529,000	$	(73,517,151	)	$	103,011,849

At December 31, 2018, intangible assets, net consisted of the following:



	Useful Life (Years)	Gross January 1, 2018		Additions		Impairment/ Disposal		Gross December 31, 2018		Accumulated Amortization			Net December 31, 2018
Indefinite Lived Assets:
Medicare license	N/A	$	1,994,000	$	—	$	—	$	1,994,000	$	—		$	1,994,000
Amortized Intangible Assets:
Network relationships	11-15	109,883,000		—		—		109,883,000		(48,361,773		)	61,521,227
Management contracts	15	22,832,000		—		—		22,832,000		(7,447,581		)	15,384,419
Member relationships	12	6,696,000		—		—		6,696,000		(1,289,667		)	5,406,333
Patient management platform	5	2,060,000		—		—		2,060,000		(446,333		)	1,613,667
Tradename/trademarks	20	1,011,000		—		—		1,011,000		(54,763		)	956,237
		$	144,476,000	$	—	$	—	$	144,476,000	$	(57,600,117	)	$	86,875,883

Amortization expense was $16.3 million, $17.1 million and $17.5 million (including $0.3 million, $0.4 million and $0.4 million of amortization expense for exclusivity incentives) for the years ended December 31, 2019, 2018, and 2017, respectively, which is included in depreciation and amortization in the accompanying consolidated statements of income.

During the year ended December 31, 2019, the Company wrote off indefinite-lived intangible assets of $2.0 million related to Medicare licenses it acquired as part of the Merger. The Company will no longer utilize these licenses and as such the Company will not receive future economic benefits.

Future amortization expense is estimated to be as follows for the years ending December 31:



	Amount

2020	$	16,026,000
2021	14,542,000
2022	12,673,000
2023	10,842,000
2024	9,830,000
Thereafter	39,099,000

	$	103,012,000