PATENTS, NET OF ACCUMULATED AMORTIZATION

9 Months Ended

Sep. 30, 2021

Patents Net Of Accumulated Amortization

PATENTS, NET OF ACCUMULATED AMORTIZATION

5. PATENTS, NET OF ACCUMULATED AMORTIZATION

Acacia’s only identifiable intangible assets as of September 30, 2021 and December 31, 2020 are patents and patent rights. Patent-related accumulated amortization totaled $291.6 million and $319.9 million as of September 30, 2021 and December 31, 2020, respectively. Acacia’s patents have remaining estimated economic useful lives ranging from twenty-six to fifty-two months. The weighted average remaining estimated economic useful life of Acacia’s patents is approximately four years.

The following table presents the scheduled annual aggregate amortization expense as of September 30, 2021: 

For the years ending December 31,
(In thousands)
Remainder of 2021	$	2,612
2022		10,448
2023		10,381
2024		9,005
2025		6,630
Thereafter		750
Patents, net	$	39,826

For the nine months ended September 30, 2021, Acacia accrued patent and patent rights acquisition costs totaling $13.0 million, of which $8.0 million is due December 1, 2021 and $5.0 million is due February 18, 2023. Such amounts are included in accrued patent investment costs and other long-term liabilities in the consolidated balance sheet as of September 30, 2021, respectively.