BENEFIT PLANS

The Company has funded defined benefit plans in Japan and the United States, however the U.S. plan was frozen to new participants effective October 1, 2013. The Company also maintains non-qualified, unfunded supplemental retirement plans that provide defined pension benefits in excess of limits imposed by federal tax law for certain Japanese, U.S. and former employees, however the U.S. plan was frozen to new participants effective January 1, 2015. U.S. employees who are not participants in the defined benefit plan receive a nonelective 401(k) employer contribution.

The Company provides certain health care benefits for eligible U.S. retired employees, their beneficiaries and covered dependents ("other postretirement benefits"). The health care plan is contributory and unfunded. Effective January 1, 2014, employees eligible for benefits included the following: (1) active employees whose age plus service, in years, equaled or exceeded 80 (rule of 80); (2) active employees who were age 55 or older and have met the 15 years of service requirement; (3) active employees who would meet the rule of 80 in the next five years; (4) active employees who were age 55 or older and who would meet the 15 years of service requirement within the next five years; and (5) current retirees. For certain employees and former employees, additional coverage is provided for all medical expenses for life.

Pension and other postretirement benefit expenses are included in acquisition and operating expenses in the consolidated statement of earnings, which includes $5 million of other components of net periodic pension cost and postretirement costs (other than service costs) for the three months ended March 31, 2018 and 2017, respectively. Total net periodic cost includes the following components:



	Three Months Ended March 31,
	Pension Benefits																Other
	Japan								U.S.								Postretirement Benefits
(In millions)	2018				2017				2018				2017				2018			2017
Components of net periodic benefit cost:
Service cost		$	5			$	5			$	7			$	6			$	0		$	0
Interest cost		2				1				9				8				0			0
Expected return on plan assets		(2		)		(1		)		(7		)		(6		)		0			0
Amortization of net actuarial loss		0				0				4				3				0			0
Amortization of prior service cost (credit)		0				0				0				0				0			0
Net periodic (benefit) cost		$	5			$	5			$	13			$	11			$	0		$	0

During the three months ended March 31, 2018, Aflac Japan contributed approximately $6 million (using the weighted-average yen/dollar exchange rate for the three-month period ending March 31, 2018) to the Japanese funded defined benefit plan, and Aflac U.S. contributed $10 million to the U.S. funded defined benefit plan.

As a result of U.S. tax reform legislation enacted in December 2017, the Company announced it would make a one-time contribution of $500 to the U.S. 401(k) plan to all employees active on December 31, 2017. This contribution was made by January 31, 2018. The Company also announced that it would increase its matching contributions to 100% of each employee's contributions which were not in excess of 4% of the employee's annual cash compensation. This increase became effective on January 1, 2018.

For additional information regarding the Company's Japanese and U.S. benefit plans, see Note 14 of the Notes to the Consolidated Financial Statements in the 2017 Annual Report.