Retirement and Postretirement Benefit Plans

The following tables set forth the components of the net periodic benefit costs for Occidental’s defined benefit plans for the three and nine months ended September 30, 2018, and 2017 (in millions):



Three months ended September 30	2018					2017
Net Periodic Benefit Costs	Pension Benefit			Postretirement Benefit		Pension Benefit			Postretirement Benefit

Service cost	$	—		$	5	$	2		$	5
Interest cost	4			8		4			9
Expected return on plan assets	(7		)	—		(6		)	—
Recognized actuarial loss	2			2		2			3
Additional settlement cost	3			—		—			—
Total	$	2		$	15	$	2		$	17



Nine months ended September 30	2018					2017
Net Periodic Benefit Costs	Pension Benefit			Postretirement Benefit		Pension Benefit			Postretirement Benefit

Service cost	$	4		$	17	$	6		$	15
Interest cost	12			26		12			29
Expected return on plan assets	(19		)	—		(18		)	—
Recognized actuarial loss	4			12		6			11
Additional settlement cost	3			—		—			—
Total	$	4		$	55	$	6		$	55

Occidental contributed approximately $2 million and $1 million in the three months ended September 30, 2018, and 2017, and approximately $4 million and $3 million in the nine months ended September 30, 2018, and 2017, to its defined benefit plans.

During the third quarter of 2018, Occidental adopted a postretirement benefit plan design change, which replaced the previous self-insured benefit with a Medicare Advantage PPO plan for Medicare-eligible retirees. As a result of this change, the postretirement benefit obligation was remeasured as of August 31, 2018. The remeasurement resulted in a decrease to the benefit obligation of $178 million, with a corresponding offset to accumulated other comprehensive income.