Commitments

Leases

Our corporate headquarters and primary manufacturing facilities are located in San Diego, California. We lease approximately 219,000 square feet of space in San Diego under leases that expire in February and March 2022. We have the option to renew each of these leases for two additional five-year terms. We lease approximately 87,000 square feet of space in San Diego under a lease that expires in February 2022 with no renewal options. We also lease approximately 132,600 square feet of space in San Diego under a sublease that expires in January 2022.

We lease approximately 148,800 square feet of space in Mesa, Arizona under a lease that expires in March 2028. We have the option to renew this lease for four additional five-year terms. The Mesa lease is a build-to-suit arrangement for a manufacturing facility where we were involved in the design and construction of the leased space, including non-standard tenant improvements that we paid for. For accounting purposes, we were considered the owner of the construction project during the construction period; as a result, during 2016 we capitalized the $6.0 million fair value of the Mesa building in property and equipment and recorded a corresponding financing lease obligation liability of $6.0 million in other liabilities in our balance sheet. We concluded that the Mesa lease does not qualify for “sale-leaseback” treatment due to prohibited continuing involvement, so we have treated the Mesa lease as a financing arrangement.

We have also entered into other operating lease agreements, primarily for office and warehouse space, that expire at various times through July 2026.

Future minimum rental obligations under all lease agreements as of December 31, 2018 were as shown in the table below. These obligations exclude real estate taxes, operating costs and tenant improvement allowances and include the financing lease obligation for our Mesa facility.



Fiscal Year Ending	(In millions)
2019	$	14.4
2020	16.9
2021	17.3
2022	6.6
2023	4.7
Thereafter	8.9
Total	$	68.8

Total rent expense for the twelve months ended December 31, 2018, 2017 and 2016 was $12.5 million, $11.1 million and $9.0 million, respectively.

Purchase Commitments

We are party to various purchase arrangements related to our manufacturing and research and development activities, including for materials used in our CGM systems. As of December 31, 2018, we had firm purchase commitments with vendors totaling $204.0 million, most of which are due within one year.