On January 1, 2019, the Company adopted ASC 842 using the optional transition method which allows entities to initially apply the lease accounting transition requirements at the adoption date and recognize a cumulative effect adjustment to the opening balance sheet of retained earnings in the period of adoption without restating comparative prior periods presented. The Company recorded operating lease right of use assets of $17.0 million and operating lease liabilities of $21.0 million as of January 1, 2019. The difference between the right of use assets and the lease liabilities was due to $4.0 million of unamortized lease incentives and deferred rent at the Company’s Waltham and Marlborough facilities as of December 31, 2018.

The Company is a lessee under leases of manufacturing facilities, office spaces, machinery, certain office equipment, vehicles and information technology equipment. A majority of the Company’s leases are operating leases with remaining lease terms between two months and 11 years. Finance leases are immaterial to the Company’s consolidated financial statements. The Company determines if an arrangement qualifies as a lease and what type of lease it is at inception. The Company elected the package of practical expedients permitted under the transition guidance within the new lease standard, which among other things, allowed it to continue to account for existing leases based on the historical lease classification. The Company also elected the practical expedients to combine lease and

non-lease

components and to exclude right of use assets and lease liabilities for leases with an initial term of 12 months or less from the balance sheet.

Some of the lease agreements the Company enters into include Company options to either extend and/or early terminate the lease, the costs of which are included in the Company’s operating lease liabilities to the extent that such options are reasonably certain of being exercised. Leases with renewal options allow the Company to extend the lease term typically between 1 and 5 years per option, some of its leases have multiple options to extend.

When determining if a renewal option is reasonably certain of being exercised, the Company considers several economic factors, including but not limited to, the significance of leasehold improvements incurred on the property, whether the asset is difficult to replace, underlying contractual obligations, or specific characteristics unique to that particular lease that would make it reasonably certain that the Company would exercise such options.

As of December 31, 2019, operating lease right of use assets were $25.7 million and operating lease liabilities were $30.6 million. Two material leases, as defined under ASC 842, to expand

the Company’s

facility in Waltham, Massachusetts commenced during the third quarter of 2019. As a result, the operating right of use asset and operating lease liability balances increased by a total of $6.1 million on their commencement dates. Amounts related to financing leases were immaterial. The maturity of the Company’s operating lease liabilities as of December 31, 2019 are as follows (amounts in thousands):


As of December 31, 2019	Amount
2020	$	3,692
2021		5,812
2022		4,830
2023		3,911
2024		3,514
2025 and thereafter		16,511

Total future minimum lease payments		38,270
Less: amount of lease payment representing interest		7,718

Total operating lease liabilities	$	30,552

Total operating lease liabilities is included on the Company’s consolidated balance sheet is as follows (amounts in thousands):


	As of December 31, 2019
Operating lease liability	$	3,557
Operating lease liability, long-term		26,995

Minimum operating lease payments	$	30,552

Lease expense for these leases is recognized on a straight-line basis over the lease term, with variable lease payments recognized in the period those payments are incurred. For the year ended December 31, 2019, total lease cost is comprised of the following:


	Year Ended
Lease Cost	December 3 1 , 2019
	(Amounts in thousands)
Operating lease cost	$	4,480
Variable operating lease cost		1,480

Lease cost	$	5,960

The following information represents supplemental disclosure for the consolidated statements of cash flows related to operating leases (amounts in thousands):


	Year Ended
	December 31, 2019
Operating cash flows from operating leases	$	(4,004	)

Most of the leases do not provide implicit interest rates and therefore the Company determines the discount rate based on its incremental borrowing rate. The incremental borrowing rate for the Company’s leases is determined based on lease term and currency in which the lease payments are made.

The weighted average remaining lease term and the weighted average discount rate used to measure the Company’s operating lease liabilities as of December 31, 2019 were:


Weighted average remaining lease term (years)	8.05
Weighted average discount rate	4.91	%