Commitments

Centene and its subsidiaries lease office facilities and various equipment under non-cancelable operating leases which may contain escalation provisions. The rental expense related to these leases is recorded on a straight-line basis over the lease term, including rent holidays. Tenant improvement allowances are recorded as a liability and amortized against rent expense over the term of the lease. Rent expense was $171 million, $137 million and $64 million for the years ended December 31, 2017, 2016 and 2015, respectively. Annual non-cancelable minimum lease payments over the next five years and thereafter are as follows ($ in millions):



2018	$	146
2019	153
2020	138
2021	116
2022	73
Thereafter	167
	$	793

In connection with obtaining regulatory approval of the Health Net acquisition from the California Department of Insurance and the California Department of Managed Health Care, the Company committed to certain undertakings. See Note 3, Health Net for further details.