PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS

This note provides details about defined benefit and defined contribution plans we sponsor for our employees. The Pension and Other Postretirement Benefit Plans section of Note 1: Summary of Significant Accounting Policies provides information about employee eligibility for pension plans and postretirement health care and life insurance benefits, as well as how we account for the plans and benefits.

DEFINED BENEFIT PLANS WE SPONSOR

OVERVIEW OF PLANS

The defined benefit pension plans we sponsor in the U.S. and Canada differ according to each country’s requirements. In the U.S., we have qualified plans that qualify under the Internal Revenue Code and nonqualified plans for select employees that provide additional benefits not qualified under the Internal Revenue Code. In Canada, we have registered plans that are registered under the Income Tax Act and applicable provincial pension acts and nonregistered plans for select employees that provide additional benefits that may not be registered under the Income Tax Act or provincial pension acts. We also offer other postretirement benefit plans in the U.S. and Canada, including retiree medical and life insurance plans.

Assumed Plans from Merger with Plum Creek

Upon our merger with Plum Creek, we assumed one qualified pension plan and two nonqualified pension plans. These plans were frozen as of February 19, 2016, and all plans were merged into existing Weyerhaeuser plans effective December 31, 2016.

The fair values of items assumed are included as plan acquisitions in the following tables. We also assumed assets of $47 million related to the nonqualified plans held in a grantor trust. These assets are subject to the claims of creditors in the event of bankruptcy. As a result, these are not considered plan assets and are not netted against the nonqualified pension liability. These assets are included in "Other assets" in our Consolidated Balance Sheet. During 2016 and 2017, we redeemed $42 million of these assets to make nonqualified pension benefit payments.

During first quarter 2016, we recognized $5 million of pension benefit costs from change in control provisions for certain Plum Creek executives. These enhanced pension benefits were triggered by changes in control and retention decisions made after the completion of the merger (see Note 17: Charges for Integration and Restructuring, Closures and Asset Impairments).

Amendments of Pension and Other Postretirement Benefit Plans for Salaried Employees

There were no material pension plan, postretirement medical or life insurance plan amendments in 2017. Aside from the December 31, 2016, amendments to merge the Plum Creek plans into the Weyerhaeuser plans as described above, there were no material plan amendments in 2016. There were also no material plan amendments in 2015.

FUNDED STATUS OF PLANS

The funded status of the plans we sponsor is determined by comparing the projected benefit obligation with the fair value of plan assets at the end of the year. The following table demonstrates how our plans' funded status is reflected on the Consolidated Balance Sheet.



DOLLAR AMOUNTS IN MILLIONS
	PENSION						OTHER POSTRETIREMENT BENEFITS
	2017			2016			2017			2016
Funded status:
Fair value of plan assets	$	5,514		$	5,351		$	—		$	—
Projected benefit obligations	(6,795		)	(6,469		)	(200		)	(225		)
Funded status	$	(1,281	)	$	(1,118	)	$	(200	)	$	(225	)
Presentation on our Consolidated Balance Sheet:
Noncurrent assets	$	45		$	27		$	—		$	—
Current liabilities	(21		)	(28		)	(19		)	(21		)
Noncurrent liabilities	(1,305		)	(1,117		)	(181		)	(204		)
Funded status	$	(1,281	)	$	(1,118	)	$	(200	)	$	(225	)

Assets and liabilities on the Consolidated Balance Sheet are different from the cumulative income or expense that we have recorded associated with the plans. The differences are actuarial gains and losses and prior service costs and credits that are deferred and amortized into periodic benefit costs in future periods. Unamortized amounts are recorded in "Cumulative Other Comprehensive Loss", which is a component of total equity on our Consolidated Balance Sheet. The "Cumulative Other Comprehensive Income (Loss)" section of Note 15: Shareholder's Interest details changes in these amounts by component.

Changes in Fair Value of Plan Assets



DOLLAR AMOUNTS IN MILLIONS
	PENSION						OTHER POSTRETIREMENT BENEFITS
	2017			2016			2017			2016
Fair value of plan assets at beginning of year (estimated)	$	5,351		$	5,491		$	—		$	—
Adjustment for final fair value of plan assets	18			7			—			—
Actual return on plan assets	553			27			—			—
Foreign currency translation	59			29			—			—
Employer contributions and benefit payments	57			78			20			21
Plan participants’ contributions	—			—			6			7
Plan transfers	3			1			—			—
Plan acquisitions	—			137			—			—
Benefits paid (includes lump sum settlements)	(527		)	(419		)	(26		)	(28		)
Fair value of plan assets at end of year (estimated)	$	5,514		$	5,351		$	—		$	—

We estimate the fair value of pension plan assets based upon the information available during the year-end reporting process. In some cases, primarily private equity funds, the available information consists of net asset values as of an interim date, plus cash flows and market events between the interim date and the end of the year. We update the year-end estimated fair value of pension plan assets during the first half of the next year to incorporate year-end net asset values received after we have filed our Annual Report on Form 10-K.

See additional details about the changes in the fair value of plan assets in the "Pension Assets" section below.

Changes in Projected Benefit Obligations of Our Pension and Other Postretirement Benefit Plans



DOLLAR AMOUNTS IN MILLIONS
	PENSION						OTHER POSTRETIREMENT BENEFITS
	2017			2016			2017			2016
Reconciliation of projected benefit obligation:
Projected benefit obligation beginning of year	$	6,469		$	6,211		$	225		$	240
Service cost	35			48			—			—
Interest cost	264			277			8			8
Plan participants’ contributions	—			—			6			7
Actuarial (gains) losses	489			120			(18		)	(5		)
Foreign currency translation	59			27			5			3
Benefits paid (includes lump sum settlements)	(527		)	(419		)	(26		)	(28		)
Plan amendments and other	3			—			—			—
Plan transfers	3			1			—			—
Plan acquisitions	—			199			—			—
Change in control enhanced benefits	—			5			—			—
Projected benefit obligation at end of year	$	6,795		$	6,469		$	200		$	225

See additional details about the actuarial assumptions and changes in the projected benefit obligation in the "Actuarial Assumptions" section below.

Accumulated Benefit Obligations Greater Than Plan Assets

As of December 31, 2017, pension plans with accumulated benefit obligations greater than plan assets had:


•	$5.9 billion in projected benefit obligations,


•	$5.9 billion in accumulated benefit obligations and


•	assets with a fair value of $4.6 billion.

As of December 31, 2016, pension plans with accumulated benefit obligations greater than plan assets had:


•	$5.7 billion in projected benefit obligations,


•	$5.6 billion in accumulated benefit obligations and


•	assets with a fair value of $4.5 billion.

The accumulated benefit obligation for all of our defined benefit pension plans was:


•	$6.7 billion at December 31, 2017, and


•	$6.4 billion at December 31, 2016.

PENSION ASSETS

Our Investment Policies and Strategies

Our investment policies and strategies guide and direct how the funds are managed for the benefit plans we sponsor. These funds include our:


•	U.S. Pension Trust — funds our U.S. qualified pension plans;


•	Canadian Pension Trust — funds our Canadian registered pension plans; and


•	Retirement Compensation Arrangements — fund a portion of our Canadian nonregistered pension plans.

U.S. and Canadian Pension Trusts

Investment managers of our pension plan asset portfolios use a diversified set of investment strategies. Our trusts invest both directly in a diversified mix of nontraditional investments, and indirectly through derivatives to promote effective use of capital, increase returns and manage associated risk. Our direct investments include cash and short-term investments, common and preferred stocks, hedge funds and related investments and private equity and related investments. Our indirect investments include equity and fixed income index derivatives, foreign currency derivatives and total return swaps.

Cash and short-term investments include highly liquid money market and government securities and are primarily held to fund benefit payments, capital calls, margin requirements or to meet regulatory requirements.

Common and preferred stocks are equity instruments that have been purchased directly or resulted from transactions related to private equity investment holdings.

Hedge fund and related investments are privately-offered managed pools primarily structured as limited liability entities. General members or partners of these limited liability entities serve as portfolio managers and are thus responsible for the fund’s underlying investment decisions. Underlying investments within these funds may include long and short public and private equities, corporate, mortgage and sovereign debt, options, swaps, forwards and other derivative positions. These funds have varying degrees of leverage, liquidity, and redemption provisions.

Private equity and related investments are investments in private equity, mezzanine, distressed, co-investments and other structures. Private equity funds generally participate in buyouts and venture capital of limited liability entities through unlisted equity and debt instruments. These funds may also borrow at the underlying entity level. Mezzanine and distressed funds generally invest in the debt of public or private companies with additional participation through warrants or other equity options.

Derivative instruments are comprised of swaps, futures, forwards or options. Equity and fixed income index derivatives are used to achieve target equity and bond exposure or to reduce exposure to certain market risks. Foreign currency derivatives reduce exposure to certain currency risks. Total return swaps enable exposure to return characteristics of specific financial strategies with limited exchange of principal.

While we do not target specific direct investment or derivative allocations, we have established guidelines on the percentage of pension trust assets that can be invested in certain categories to provide diversification by investment type fund and investment managers, as well as to manage overall liquidity. Allocation of trust assets at the end of the last two years is presented below.

Assets within our qualified and registered pension plans in our U.S. and Canadian pension trusts were invested as follows:



	DECEMBER 31, 2017		DECEMBER 31, 2016
Cash and short-term investments	10.6	%	13.7	%
Common and preferred stock	—		0.1
Hedge funds and related investments	58.8		56.6
Private equity and related investments	22.2		22.7
Derivative instruments, net	8.7		7.1
Accrued liabilities	(0.3	)	(0.2	)
Total	100.0	%	100.0	%

Retirement Compensation Arrangements

Retirement compensation arrangements fund a portion of our Canadian nonregistered pension plans. As required by Canadian tax rules, approximately 50 percent of these assets are invested into a noninterest-bearing refundable tax account held by the Canada Revenue Agency. This portion of the portfolio does not earn returns. The remaining portion is invested in a portfolio of equities.

Managing Risk

Investments and contracts are subject to risks including market price, liquidity, currency, interest rate and credit risks. The following provides an overview of these risks and describes governance processes and actions we take to mitigate these risks on our pension plan asset portfolios.

Market price risk is the risk that market fluctuations will adversely affect the value of plan assets. The trusts mitigate market price risk by investing in a diversified portfolio whose returns exhibit low correlation to traditional asset classes and to each other. In addition, we and our investment advisers perform regular monitoring with ongoing qualitative assessments, quantitative assessments, and comprehensive investment and operational due diligence.

Liquidity risk is the risk that the trust will not be able to settle liabilities such as payments to participants, counterparties, and service providers. Plan investments in limited liability pools with no active secondary market may be illiquid. Private equity funds are subject to distribution and funding schedules set by fund managers and market activity. Hedge funds may also be subject to restrictions that delay redemptions. To mitigate liquidity risk, private equity portfolios have been diversified across different vintage years and strategies, and hedge fund portfolios have been diversified across investment fund managers, strategies and liquidity provisions. In addition, the investment committee regularly reviews cash flows of the pension trusts and sets appropriate guidelines to address liquidity needs.

Currency risk arises from holding plan assets denominated in a currency other than the currency in which its liabilities are settled. Currency risk is generally managed through notional contracts designed to hedge net exposure to non-functional currencies.

Interest rate risk is the risk that a change in interest rates will adversely affect the fair value of fixed income securities. Interest rate risk exposure is primarily indirect through investment in limited liability pools. Fund managers mitigate this risk with predefined investment mandates and investment decisions.

Credit risk is the risk that counterparties’ failure to discharge their obligations could impact cash flows. The trusts’ primary exposure is through settlement receivables from derivative contracts. Only the amount of unsettled net receivables is at risk for these types of investments, and no principal is at risk. We decrease credit risk exposure by only dealing with highly-rated financial counterparties; as of year-end, our counterparties each had a credit rating of at least A from S&P. We further manage this risk through diversification of counterparties, predefined settlement and margining provisions and documented agreements.

We are also exposed to credit risk indirectly through counterparty relationships initiated by underlying managers of investments in limited liability pools. This risk is mitigated through initial due diligence and ongoing monitoring processes.

Valuation of Our Plan Assets

Pension assets are stated at fair value as of the reporting date. Fair value is based on the amount that would be received to sell an asset or paid to settle a liability in an orderly transaction between market participants at the reporting date. We do not consider forced or distressed sale scenarios. Instead, we consider both observable and unobservable inputs that reflect assumptions applied by market participants when setting the exit price of an asset or liability in an orderly transaction within the principal market for that asset or liability.

We value the pension plan assets based upon the observability of exit pricing inputs and classify pension plan assets based upon the lowest level input that is significant to the fair value measurement of the pension plan assets in their entirety. The fair value hierarchy is:


•	Level 1: Inputs are unadjusted quoted prices for identical assets and liabilities traded in an active market.


•	Level 2: Inputs are quoted prices in non-active markets for which pricing inputs are observable either directly or indirectly at the reporting date.


•	Level 3: Inputs are derived from valuation techniques in which one or more significant inputs or value drivers are unobservable.

Investments for which fair value is measured using the net asset value per share as a practical expedient are not categorized within the fair value hierarchy.

Cash and short-term investments are valued at cost, which approximates market.

Common and preferred stocks are valued at exit prices quoted in public markets.

Hedge funds, private equities, and related fund units are valued based on the net asset values of the funds. These values represent the per-unit price at which new investors are permitted to invest and existing investors are permitted to exit. When net asset values as of the end of the year have not been received, we estimate fair value by adjusting the most recently reported net asset values for market events and cash flows between the interim date and the end of the year.

Derivative instruments are valued based upon valuation statements received from each derivative’s counterparty. These contracts are not publicly traded.

The net pension plan assets, when categorized in accordance with this fair value hierarchy, are as follows. Investments valued using net asset value (NAV) as a practical expedient are presented to reconcile with total plan assets.



DOLLAR AMOUNTS IN MILLIONS
2017	LEVEL 1		LEVEL 2		LEVEL 3		NAV		TOTAL
Pension trust investments:
Cash and short-term investments	$	580	$	2	$	—	$	—	$	582
Common and preferred stock	1		—		—		—		1
Hedge fund and related investments	59		—		10		3,168		3,237
Private equity and related investments	—		—		102		1,120		1,222
Derivative instruments:
Assets	—		31		445		—		476
Liabilities	—		—		—		—		—
Total pension trust investments	640		33		557		4,288		5,518
Accrued liabilities, net									(16		)
Pension trust net assets									5,502
Canadian nonregistered plan assets:
Cash and short-term investments	6		—		—		—		6
Common and preferred stock	6		—		—		—		6
Total Canadian nonregistered plan assets	12		—		—		—		12
Total plan assets									$	5,514



DOLLAR AMOUNTS IN MILLIONS
2016	LEVEL 1		LEVEL 2			LEVEL 3		NAV		TOTAL
Pension trust investments:
Cash and short-term investments	$	715	$	16		$	—	$	—	$	731
Common and preferred stock	7		—			—		—		7
Hedge fund and related investments	62		—			4		2,957		3,023
Private equity and related investments	—		—			75		1,138		1,213
Derivative instruments:
Assets	—		10			376		—		386
Liabilities	—		(8		)	—		—		(8		)
Total pension trust investments	784		18			455		4,095		5,352
Accrued liabilities, net										(11		)
Pension trust net investments										5,341
Canadian nonregistered plan assets:
Cash and short-term investments	5		—			—		—		5
Common and preferred stock	5		—			—		—		5
Total Canadian nonregistered plan assets	10		—			—		—		10
Total plan assets										$	5,351

Assets that do not have readily available quoted prices in an active market require more judgment to value and have increased risk. Approximately $557 million, or 10.1 percent, of our pension plan assets were classified as Level 3 assets as of December 31, 2017.

A reconciliation of the beginning and ending balances of the pension plan assets measured at fair value using significant unobservable inputs (Level 3) is presented below:



DOLLAR AMOUNTS IN MILLIONS
	INVESTMENTS
	Hedge funds and related investments			Private equity and related investments			Derivative instruments, net			Total
Balance as of December 31, 2015	$	3		$	52		$	491		$	546
Net realized gains (losses)	(1		)	(2		)	134			131
Net change in unrealized gains (losses)	2			(3		)	(121		)	(122		)
Purchases	—			21			—			21
Sales	—			(18		)	—			(18		)
Settlements	—			—			(128		)	(128		)
Transfers into Level 3	—			25			—			25
Transfers out of Level 3	—			—			—			—
Balance as of December 31, 2016	4			75			376			455
Net realized gains (losses)	(1		)	(30		)	15			(16		)
Net change in unrealized gains (losses)	2			41			67			110
Purchases	—			14			—			14
Sales	(1		)	—			—			(1		)
Settlements	—			—			(13		)	(13		)
Transfers into Level 3	6			19			—			25
Transfers out of Level 3	—			(17		)	—			(17		)
Balance as of December 31, 2017	$	10		$	102		$	445		$	557

The availability of observable market data is monitored to assess the appropriate classification of financial instruments within the fair value hierarchy. Changes in economic conditions or model-based valuation techniques may require the transfer of financial instruments from one fair value level to another. In such instances, the transfer is reported at the beginning of the reporting period. We evaluate the significance of transfers between levels based upon the nature of the financial instrument and size of the transfer relative to total net assets available for benefits.

The table below shows the fair value and aggregate notional amount of the derivative instruments held by our pension trusts at the end of the last two years.



DOLLAR AMOUNTS IN MILLIONS
	FAIR VALUE					NOTIONAL
	DECEMBER 31, 2017		DECEMBER 31, 2016			DECEMBER 31, 2017		DECEMBER 31, 2016
Equity and fixed income index derivatives, net	$	19	$	10		$	501	$	405
Foreign currency derivatives, net	12		(5		)	1,413		2,811
Total return swaps, net	445		373			1,443		1,515
Total	$	476	$	378		$	3,357	$	4,731

ACTUARIAL ASSUMPTIONS

We use actuarial assumptions to estimate our benefit obligations and our net periodic benefit costs. The following tables show the rates used to estimate our benefit obligations and periodic net benefit costs.

Rates We Use in Estimating Our Benefit Obligations



	PENSION
	DECEMBER 31, 2017		DECEMBER 31, 2016
Discount rates:
United States	3.70	%	4.30	%
Canada	3.50	%	3.70	%
Lump sum distributions⁽¹⁾⁽²⁾	PPA Table		PPA Table
Rate of compensation increase:
Salaried:
United States	13.00% to 2.00% decreasing with participant age		13.00% to 2.00% decreasing with participant age
Canada	3.25	%	3.50	%
Hourly:
United States	13.00% to 2.30% decreasing with participant age		13.00% to 2.30% decreasing with participant age
Canada	3.00	%	3.25	%
Lump sum or installment distributions election⁽²⁾	60.00	%	60.00	%
(1) PPA Phased Table: Interest and mortality assumptions as mandated by Pension Protection Act of 2006 including the phase out of the prior interest rate basis in 2013. (2) U.S. qualified salaried and nonqualified plans only

The discount rates used for our U.S. other postretirement benefit plans were 3.50 percent and 3.70 percent for the years ended December 31, 2017, and December 31, 2016, respectively. Additionally, the discount rates used for our Canadian other postretirement benefit plans were 3.40 percent and 3.60 percent for the years ended December 31, 2017, and December 31, 2016, respectively.

Estimating Our Net Periodic Benefit Costs



	PENSION
	2017		2016		2015
Discount rates:
United States	4.30	%	4.50	%	4.10	%
Canada	3.70	%	4.00	%	3.90	%
Lump sum distributions⁽¹⁾⁽²⁾	PPA Table		PPA Table		PPA Table
Expected return on plan assets:
Qualified/registered plans⁽³⁾	8.00	%	9.00% for all plans except 7.00% for plans assumed from Plum Creek		9.00	%
Nonregistered plans	3.50	%	3.50	%	3.50	%
Rate of compensation increase:
Salaried:
United States	13.00% to 2.00% decreasing with participant age		13.00% to 2.00% decreasing with participant age		2.50% for 2015 and 3.50% thereafter
Canada	3.50	%	3.50	%	2.50% for 2015 and 3.50% thereafter
Hourly:
United States	13.00% to 2.30% decreasing with participant age		13.00% to 2.30% decreasing with participant age		3.00	%
Canada	3.25	%	3.25	%	3.25	%
Lump sum distributions election⁽²⁾	60.00	%	60.00	%	60.00	%
(1) PPA Phased Table: Interest and mortality assumptions as mandated by Pension Protection Act of 2006 including the phase out of the prior interest rate basis in 2013. (2) U.S. qualified salaried and nonqualified plans only (3) Beginning in 2017 and continuing in 2018 we will use an assumed expected return on plan assets of 8.00 percent for qualified and registered pension plans.

The discount rates used for our U.S. other postretirement benefit plans were 3.70 percent, 4.00 percent and 3.60 percent for the years ended December 31, 2017, December 31, 2016, and December 31, 2015, respectively. Additionally, the discount rates used for our Canadian other postretirement benefit plans were 3.60 percent, 3.90 percent and 3.80 percent for the years ended December 31, 2017, December 31, 2016, and December 31, 2015, respectively.

Expected Return on Plan Assets

We estimate the expected long-term return on assets for our qualified, registered and nonregistered pension plans.

Qualified and Registered Pension Plans

We have assumed a long-term rate of return on plan assets of 8 percent for the year ended December 31, 2017. As part of our 2016 annual evaluation of key assumptions, we reduced our assumption of long-term rate of return on plan assets to 8 percent for estimated 2017 net periodic benefit cost.

Determining our expected return requires a high degree of judgment. We consider actual pension fund performance over multiple years, and current and expected valuation levels in the global equity and credit markets. Historical fund returns are used as a base, and we place added weight on more recent pension plan asset performance. Over the 33 years it has been in place, our U.S. pension trust investment strategy has achieved a 13.7 percent net compound annual return rate. The past 5 years, our net compounded annual return was over 8 percent.

Nonregistered Plans

Canadian tax rules require that 50 percent of the assets for nonregistered plans go to a noninterest-bearing refundable tax account. As a result, the return we earn investing the other 50 percent is spread over 100 percent of the assets. Our expected long-term annual rate of return on the portion we are allowed to manage is 7 percent. This assumption is based on historical experience and future return expectations. The expected overall annual return on assets that fund our nonregistered plans is 3.5 percent.

Allocation of Actual Returns Between Assets Held by Our Pension Trusts

The percentage of actual return on assets held by our pension trusts in 2017 based on valuations as of year-end is as follows:




	2017		2016		2015
Direct investments	72	%	44	%	77	%
Derivative instruments	28	%	56	%	23	%
Total	100	%	100	%	100	%

Health Care Costs

Rising costs of health care affect the costs of our other postretirement plans. We use assumptions about health care cost trend rates to estimate the cost of benefits we provide. Our trend rate assumptions are based on historical market experience, current environment and future expectations. In 2017, the assumed weighted health care cost trend rate was:


•	8.9 percent for U.S. Pre-Medicare


•	4.5 percent for U.S. Health Reimbursement Account (HRA)


•	4.9 percent for Canada

This table shows the assumptions we use in estimating the annual cost increase for health care benefits we provide.

Assumptions We Use in Estimating Health Care Benefit Cost Trends



	2017				2016
	U.S.		CANADA		U.S.		CANADA
Weighted health care cost trend rate assumed for next year	8.40% for Pre-Medicare and 4.50% for HRA		5.10	%	8.90% for Pre-Medicare and 4.50% for HRA		4.90	%
Rate that the cost trend rate gradually declines to	4.50	%	4.30	%	4.50	%	4.30	%
Year the cost trend rate is reached	2037		2028		2037		2028

The assumed health care cost trend rate can significantly influence projected postretirement benefit plan payments. The following table demonstrates the effect a one percent change in assumed health care cost trend rates would have with all other assumptions remaining constant.

Effect of a One Percent Change in Health Care Costs

ACTIVITY OF PLANS

Net Periodic Benefit Cost (Credit)



DOLLAR AMOUNTS IN MILLIONS
	PENSION									OTHER POSTRETIREMENT BENEFITS
	2017			2016			2015			2017			2016			2015
Net periodic benefit cost (credit):
Service cost⁽¹⁾	$	35		$	48		$	57		$	—		$	—		$	—
Interest cost	264			277			265			8			8			9
Expected return on plan assets	(409		)	(495		)	(476		)	—			—			—
Amortization of actuarial loss	195			156			182			8			9			10
Amortization of prior service cost (credit)	4			4			4			(8		)	(7		)	(9		)
Accelerated pension costs for Plum Creek merger-related change-in-control provisions	—			5			—			—			—			—
Net periodic benefit cost (credit)	$	89		$	(5	)	$	32		$	8		$	10		$	10
(1) Service cost includes $13 million in 2016 and $17 million in 2015 for employees that were part of our Cellulose Fibers divestitures. These charges are included in our results of discontinued operations. Curtailment and special termination benefits are related to involuntary terminations due to restructuring activities.

Estimated Amortization from Cumulative Other Comprehensive Loss in 2018



DOLLAR AMOUNTS IN MILLIONS
	PENSION		OTHER POSTRETIREMENT BENEFITS			TOTAL
Net actuarial loss	$	242	$	8		$	250
Prior service cost (credit)	3		(8		)	(5		)
Net effect cost	$	245	$	—		$	245

Expected Pension Plan and Benefit Funding

Established funding standards govern the funding requirements for our qualified and registered pension plans. We fund the benefit payments of our nonqualified and nonregistered plans as benefit payments come due. There was no minimum required contribution for our U.S. qualified plan for 2017, nor were any contributions made to this plan in 2017. During 2017, we contributed $25 million for our Canadian registered plans, we made contributions and benefit payments of $2 million for our Canadian nonregistered pension plans and made benefit payments of $31 million for our nonqualified pension plans, including $1 million of enhanced pension benefit payments from change in control provisions.

During 2018, based on estimated year-end asset values and projections of plan liabilities, we expect to:


•	be required to contribute approximately $23 million for our Canadian registered plan;


•	be required to contribute or make benefit payments for our Canadian nonregistered plans of $4 million; and


•	make benefit payments of approximately $19 million for our U.S. nonqualified pension plans.

We do not anticipate a contribution being required for our U.S. qualified pension plan for 2018.

Expected Postretirement Benefit Funding

Benefits for these plans are paid from our general assets as they come due. We expect to make benefit payments of $19 million for our U.S. and Canadian other postretirement benefit plans in 2018, including $7 million expected to be required to cover benefit payments under collectively bargained contractual obligations.

Estimated Projected Benefit Payments for the Next 10 Years



DOLLAR AMOUNTS IN MILLIONS
	PENSION		OTHER POSTRETIREMENT BENEFITS
2018	$	369	$	19
2019	371		18
2020	374		17
2021	374		16
2022	376		15
2023-2027	1,902		65

UNION-ADMINISTERED MULTIEMPLOYER BENEFIT PLANS

We contribute to multiemployer defined benefit plans under the terms of collective-bargaining agreements. These plans cover a small number of our employees and on an annual basis our contributions are immaterial.

These plans have different risks than single-employer plans. Our contributions may be used to fund benefits for employees of other participating employers. If we choose to stop participating, we may be required to pay a withdrawal liability based on the underfunded status of the plan. If another participating employer stops contributing to the plan, we may become responsible for remaining plan unfunded obligations.

DEFINED CONTRIBUTION PLANS

We sponsor various defined contribution plans for our U.S. and Canadian salaried and hourly employees. Our contributions to these plans were:


•	$21 million in 2017,


•	$27 million in 2016 and


•	$21 million in 2015.

Upon our merger with Plum Creek, we assumed one defined contribution plan, the Plum Creek Thrift and Profit Sharing Plan. Effective July 15, 2016, the assets of this plan were merged into the Weyerhaeuser 401(k) Plan.

AS OF DECEMBER 31, 2017 (DOLLAR AMOUNTS IN MILLIONS)

1% INCREASE

1% DECREASE

Effect on total service and interest cost components

less than $1

less than $(1)

Effect on accumulated postretirement benefit obligation