Benefit Plans and Other Postretirement Benefits

Xcel Energy offers various benefit plans to its employees. Approximately 47 percent of employees that receive benefits are represented by several local labor unions under several collective-bargaining agreements. At Dec. 31, 2015:

•

NSP-Minnesota had 1,983 and NSP-Wisconsin had 400 bargaining employees covered under a collective-bargaining agreement, which expires at the end of 2016. NSP-Minnesota also had an additional 265 nuclear operation bargaining employees covered under several collective-bargaining agreements. Some of these agreements expired in 2015, but were extended to 2016. The remaining agreements expire in 2016 and 2018.


•	PSCo had 2,024 bargaining employees covered under a collective-bargaining agreement, which expires in May 2017.


•	SPS had 842 bargaining employees covered under a collective-bargaining agreement, which expired in October 2014. While collective bargaining is ongoing, the terms and conditions of the expired agreement are automatically extended until the parties reach an agreement or a decision is rendered by an arbitrator.

The plans invest in various instruments which are disclosed under the accounting guidance for fair value measurements which establishes a hierarchical framework for disclosing the observability of the inputs utilized in measuring fair value. The three levels in the hierarchy and examples of each level are as follows:

Level 1 — Quoted prices are available in active markets for identical assets as of the reporting date. The types of assets included in Level 1 are highly liquid and actively traded instruments with quoted prices.

Level 2 — Pricing inputs are other than quoted prices in active markets, but are either directly or indirectly observable as of the reporting date. The types of assets included in Level 2 are typically either comparable to actively traded securities or contracts, or priced with models using highly observable inputs.

Level 3 — Significant inputs to pricing have little or no observability as of the reporting date. The types of assets included in Level 3 are those with inputs requiring significant management judgment or estimation.

Specific valuation methods include the following:

Cash equivalents — The fair values of cash equivalents are generally based on cost plus accrued interest; money market funds are measured using quoted net asset values.

Insurance contracts — Insurance contract fair values take into consideration the value of the investments in separate accounts of the insurer, which are priced based on observable inputs.

Investments in equity securities and other funds — Equity securities are valued using quoted prices in active markets. Preferred stock is valued using recent trades and quoted prices of similar securities. The fair values for commingled funds, private equity investments and real estate investments are measured using net asset values, which take into consideration the value of underlying fund investments, as well as the other accrued assets and liabilities of a fund, in order to determine a per share market value. The investments in commingled funds may be redeemed for net asset value with proper notice. Proper notice varies by fund and can range from daily with one or two days notice to annually with 90 days notice. Private equity investments require approval of the fund for any unscheduled redemption, and such redemptions may be approved or denied by the fund at its sole discretion. Unscheduled distributions from real estate investments may be redeemed with proper notice, which is typically quarterly with 45-90 days notice; however, withdrawals from real estate investments may be delayed or discounted as a result of fund illiquidity. Based on the plan’s evaluation of its ability to redeem private equity and real estate investments, fair value measurements for private equity and real estate investments have been assigned a Level 3.

Investments in debt securities — Fair values for debt securities are determined by a third party pricing service using recent trades and observable spreads from benchmark interest rates for similar securities.

Derivative Instruments — Fair values for foreign currency derivatives are determined using pricing models based on the prevailing forward exchange rate of the underlying currencies. The fair values of interest rate derivatives are based on broker quotes that utilize current market interest rate forecasts.

Pension Benefits

Xcel Energy has several noncontributory, defined benefit pension plans that cover almost all employees. Generally, benefits are based on a combination of years of service, the employee’s average pay and, in some cases, social security benefits. Xcel Energy’s policy is to fully fund into an external trust the actuarially determined pension costs recognized for ratemaking and financial reporting purposes, subject to the limitations of applicable employee benefit and tax laws.

In addition to the qualified pension plans, Xcel Energy maintains a supplemental executive retirement plan (SERP) and a nonqualified pension plan. The SERP is maintained for certain executives that were participants in the plan in 2008, when the SERP was closed to new participants. The nonqualified pension plan provides unfunded, nonqualified benefits for compensation that is in excess of the limits applicable to the qualified pension plans. The total obligations of the SERP and nonqualified plan as of Dec. 31, 2015 and 2014 were $41.8 million and $46.5 million, respectively. In 2015 and 2014, Xcel Energy recognized net benefit cost for financial reporting for the SERP and nonqualified plans of $9.5 million and $4.7 million, respectively. Benefits for these unfunded plans are paid out of Xcel Energy’s consolidated operating cash flows.

Xcel Energy bases the investment-return assumption on expected long-term performance for each of the investment types included in its pension asset portfolio. Xcel Energy considers the historical returns achieved by its asset portfolio over the past 20-year or longer period, as well as the long-term return levels projected and recommended by investment experts. Xcel Energy continually reviews its pension assumptions. The pension cost determination assumes a forecasted mix of investment types over the long-term.


•	Investment returns in 2015 were below the assumed level of 7.09 percent;


•	Investment returns in 2014 were above the assumed level of 7.05 percent;


•	Investment returns in 2013 were below the assumed level of 6.88 percent; and


•	In 2016, Xcel Energy’s expected investment return assumption is 6.87 percent.

The assets are invested in a portfolio according to Xcel Energy’s return, liquidity and diversification objectives to provide a source of funding for plan obligations and minimize the necessity of contributions to the plan, within appropriate levels of risk. The principal mechanism for achieving these objectives is the projected allocation of assets to selected asset classes, given the long-term risk, return, and liquidity characteristics of each particular asset class. There were no significant concentrations of risk in any particular industry, index, or entity. Market volatility can impact even well-diversified portfolios and significantly affect the return levels achieved by pension assets in any year.

The following table presents the target pension asset allocations for Xcel Energy at Dec. 31 for the upcoming year:



	2015		2014
Domestic and international equity securities	39	%	37	%
Long-duration fixed income and interest rate swap securities	27		27
Short-to-intermediate fixed income securities	13		13
Alternative investments	19		21
Cash	2		2
Total	100	%	100	%

Xcel Energy’s ongoing investment strategy is based on plan-specific investment recommendations that seek to minimize potential investment and interest rate risk as a plan’s funded status increases over time. The investment recommendations result in a greater percentage of long-duration fixed income securities being allocated to specific plans having relatively higher funded status ratios and a greater percentage of growth assets being allocated to plans having relatively lower funded status ratios. The aggregate projected asset allocation presented in the table above for the master pension trust results from the plan-specific strategies.

Pension Plan Assets

The following tables present, for each of the fair value hierarchy levels, Xcel Energy’s pension plan assets that are measured at fair value as of Dec. 31, 2015 and 2014:



	Dec. 31, 2015
(Thousands of Dollars)	Level 1		Level 2		Level 3		Total
Cash equivalents	$	178,884	$	—	$	—	$	178,884
Derivatives	—		2,850		—		2,850
Government securities	—		412,932		—		412,932
Corporate bonds	—		248,439		—		248,439
Asset-backed securities	—		2,446		—		2,446
Common stock	93,831		—		—		93,831
Private equity investments	—		—		126,396		126,396
Commingled funds	—		1,759,066		—		1,759,066
Real estate	—		—		55,935		55,935
Other	—		3,001		—		3,001
Total	$	272,715	$	2,428,734	$	182,331	$	2,883,780



	Dec. 31, 2014
(Thousands of Dollars)	Level 1		Level 2			Level 3		Total
Cash equivalents	$	193,141	$	—		$	—	$	193,141
Derivatives	—		1,590			—		1,590
Government securities	—		439,186			—		439,186
Corporate bonds	—		318,161			—		318,161
Asset-backed securities	—		3,759			—		3,759
Mortgage-backed securities	—		11,047			—		11,047
Common stock	102,667		—			—		102,667
Private equity investments	—		—			151,871		151,871
Commingled funds	—		1,826,420			—		1,826,420
Real estate	—		—			54,657		54,657
Securities lending collateral obligation and other	—		(18,728		)	—		(18,728		)
Total	$	295,808	$	2,581,435		$	206,528	$	3,083,771

The following tables present the changes in Xcel Energy’s Level 3 pension plan assets for the years ended Dec. 31, 2015, 2014 and 2013:



(Thousands of Dollars)	Jan. 1, 2015		Net Realized Gains (Losses)		Net Unrealized Gains (Losses)			Purchases, Issuances and Settlements, Net			Transfers Out of Level 3		Dec. 31, 2015
Private equity investments	$	151,871	$	28,094	$	(40,848	)	$	(12,721	)	$	—	$	126,396
Real estate	54,657		7,083		(8,443		)	2,638			—		55,935
Total	$	206,528	$	35,177	$	(49,291	)	$	(10,083	)	$	—	$	182,331



(Thousands of Dollars)	Jan. 1, 2014		Net Realized Gains (Losses)		Net Unrealized Gains (Losses)			Purchases, Issuances and Settlements, Net			Transfers Out of Level 3		Dec. 31, 2014
Private equity investments	$	152,849	$	25,694	$	(17,573	)	$	(9,099	)	$	—	$	151,871
Real estate	47,553		3,569		(2,443		)	5,978			—		54,657
Total	$	200,402	$	29,263	$	(20,016	)	$	(3,121	)	$	—	$	206,528



(Thousands of Dollars)	Jan. 1, 2013		Net Realized Gains (Losses)			Net Unrealized Gains (Losses)			Purchases, Issuances and Settlements, Net			Transfers Out of Level 3 ^(a)			Dec. 31, 2013
Asset-backed securities	$	14,639	$	—		$	—		$	—		$	(14,639	)	$	—
Mortgage-backed securities	39,904		—			—			—			(39,904		)	—
Private equity investments	158,498		22,058			(24,335		)	(3,372		)	—			152,849
Real estate	64,597		(2,659		)	8,690			9,317			(32,392		)	47,553
Total	$	277,638	$	19,399		$	(15,645	)	$	5,945		$	(86,935	)	$	200,402


^(a)	Transfers out of Level 3 into Level 2 were principally due to diminished use of unobservable inputs that were previously significant to these fair value measurements and were subsequently sold during 2013.

Benefit Obligations — A comparison of the actuarially computed pension benefit obligation and plan assets for Xcel Energy is presented in the following table:



(Thousands of Dollars)	2015			2014
Accumulated Benefit Obligation at Dec. 31	$	3,368,239		$	3,545,928

Change in Projected Benefit Obligation:
Obligation at Jan. 1	$	3,746,752		$	3,440,704
Service cost	99,311			88,342
Interest cost	148,524			156,619
Actuarial (gain) loss	(169,678		)	342,826
Benefit payments	(256,982		)	(281,739		)
Obligation at Dec. 31	$	3,567,927		$	3,746,752



(Thousands of Dollars)	2015			2014
Change in Fair Value of Plan Assets:
Fair value of plan assets at Jan. 1	$	3,083,771		$	3,010,140
Actual (loss) return on plan assets	(33,102		)	224,808
Employer contributions	90,093			130,562
Benefit payments	(256,982		)	(281,739		)
Fair value of plan assets at Dec. 31	$	2,883,780		$	3,083,771



(Thousands of Dollars)	2015			2014
Funded Status of Plans at Dec. 31:
Funded status^(a)	$	(684,147	)	$	(662,981	)


^(a)	Amounts are recognized in noncurrent liabilities on Xcel Energy’s consolidated balance sheets.



(Thousands of Dollars)	2015			2014
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost:
Net loss	$	1,710,097		$	1,757,935
Prior service credit	(9,073		)	(10,878		)
Total	$	1,701,024		$	1,747,057



(Thousands of Dollars)	2015		2014
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost Have Been Recorded as Follows Based Upon Expected Recovery in Rates:
Current regulatory assets	$	105,426	$	113,432
Noncurrent regulatory assets	1,520,975		1,558,649
Deferred income taxes	29,002		29,143
Net-of-tax accumulated OCI	45,621		45,833
Total	$	1,701,024	$	1,747,057



Measurement date	Dec. 31, 2015	Dec. 31, 2014



	2015		2014
Significant Assumptions Used to Measure Benefit Obligations:
Discount rate for year-end valuation	4.66	%	4.11	%
Expected average long-term increase in compensation level	4.00		3.75
Mortality table	RP 2014		RP 2014

Mortality — In 2014, the Society of Actuaries published a new mortality table and projection scale that increased the overall life expectancy of males and females. Xcel Energy has reviewed its own population through a credibility analysis and adopted the RP 2014 table, with modifications, based on its population and specific experience. During 2015, a new projection table was released (MP 2015). Xcel Energy evaluated the updated projection table and concluded that the methodology, adopted at Dec. 31, 2014, is consistent with the recently updated table and continues to be representative of its population.

Cash Flows — Cash funding requirements can be impacted by changes to actuarial assumptions, actual asset levels and other calculations prescribed by the funding requirements of income tax and other pension-related regulations. Required contributions were made in 2013 through 2016 to meet minimum funding requirements.

Total voluntary and required pension funding contributions across all four of Xcel Energy’s pension plans were as follows:


•	$125.0 million in January 2016;


•	$90.1 million in 2015;


•	$130.6 million in 2014; and


•	$192.4 million in 2013.

For future years, Xcel Energy anticipates contributions will be made as necessary.

Plan Amendments — In 2015 and 2014 there were no plan amendments made which affected the projected benefit obligation. The 2013 decrease of the projected benefit obligation for plan amendments is due to fully insuring the long-term disability benefit for NSP bargaining participants. This decrease was partially offset by an increase to the projected benefit obligation resulting from a change in the discount rate basis for lump sum conversion of annuities for participants in the Xcel Energy Pension Plan.

Benefit Costs — The components of Xcel Energy’s net periodic pension cost were:



(Thousands of Dollars)	2015			2014			2013
Service cost	$	99,311		$	88,342		$	96,282
Interest cost	148,524			156,619			140,690
Expected return on plan assets	(213,890		)	(207,205		)	(198,452		)
Amortization of prior service (credit) cost	(1,805		)	(1,746		)	5,871
Amortization of net loss	125,152			116,762			144,151
Net periodic pension cost	157,292			152,772			188,542
Costs not recognized due to effects of regulation	(29,633		)	(26,315		)	(36,724		)
Net benefit cost recognized for financial reporting	$	127,659		$	126,457		$	151,818



	2015		2014		2013
Significant Assumptions Used to Measure Costs:
Discount rate	4.11	%	4.75	%	4.00	%
Expected average long-term increase in compensation level	3.75		3.75		3.75
Expected average long-term rate of return on assets	7.09		7.05		6.88

Pension costs include an expected return impact for the current year that may differ from actual investment performance in the plan. The return assumption used for 2016 pension cost calculations is 6.87 percent.

Defined Contribution Plans

Xcel Energy maintains 401(k) and other defined contribution plans that cover substantially all employees. Total expense to these plans was approximately $34.1 million in 2015, $32.4 million in 2014 and $30.3 million in 2013.

Postretirement Health Care Benefits

Xcel Energy has a contributory health and welfare benefit plan that provides health care and death benefits to certain Xcel Energy retirees.


•	NSP-Minnesota and NSP-Wisconsin discontinued contributing toward health care benefits for nonbargaining employees retiring after 1998 and for bargaining employees who retired after 1999.


•	Xcel Energy discontinued contributing toward health care benefits for PSCo and SPS, nonbargaining employees retiring after June 30, 2003.


•	Employees of NCE who retired in 2002 continue to receive employer-subsidized health care benefits.


•	Nonbargaining employees of the former NCE who retired after 1998, bargaining employees of the former NCE who retired after 1999 and nonbargaining employees of NCE who retired after June 30, 2003, are eligible to participate in the Xcel Energy health care program with no employer subsidy.

Plan Assets — Certain state agencies that regulate Xcel Energy Inc.’s utility subsidiaries also have issued guidelines related to the funding of postretirement benefit costs. SPS is required to fund postretirement benefit costs for Texas and New Mexico jurisdictional amounts collected in rates. PSCo is required to fund postretirement benefit costs in irrevocable external trusts that are dedicated to the payment of these postretirement benefits. These assets are invested in a manner consistent with the investment strategy for the pension plan.

The following table presents the target postretirement asset allocations for Xcel Energy at Dec. 31 for the upcoming year:



	2015		2014
Domestic and international equity securities	25	%	25	%
Short-to-intermediate fixed income securities	57		57
Alternative investments	13		13
Cash	5		5
Total	100	%	100	%

Xcel Energy bases its investment-return assumption for the postretirement health care fund assets on expected long-term performance for each of the investment types included in its asset portfolio. The assets are invested in a portfolio according to Xcel Energy’s return, liquidity and diversification objectives to provide a source of funding for plan obligations and minimize the necessity of contributions to the plan, within appropriate levels of risk. The principal mechanism for achieving these objectives is the projected allocation of assets to selected asset classes, given the long-term risk, return, correlation and liquidity characteristics of each particular asset class. There were no significant concentrations of risk in any particular industry, index, or entity. Market volatility can impact even well-diversified portfolios and significantly affect the return levels achieved by postretirement health care assets in any year.

The following tables present, for each of the fair value hierarchy levels, Xcel Energy’s postretirement benefit plan assets that are measured at fair value as of Dec. 31, 2015 and 2014:



	Dec. 31, 2015
(Thousands of Dollars)	Level 1		Level 2			Level 3		Total
Cash equivalents	$	19,638	$	—		$	—	$	19,638
Government securities	—		39,241			—		39,241
Insurance contracts	—		47,205			—		47,205
Corporate bonds	—		72,876			—		72,876
Asset-backed securities	—		28,691			—		28,691
Mortgage-backed securities	—		35,612			—		35,612
Commingled funds	—		204,782			—		204,782
Other	—		(412		)	—		(412		)
Total	$	19,638	$	427,995		$	—	$	447,633



	Dec. 31, 2014
(Thousands of Dollars)	Level 1		Level 2			Level 3		Total
Cash equivalents ^(a)	$	26,324	$	—		$	—	$	26,324
Derivatives	—		186			—		186
Government securities	—		48,584			—		48,584
Insurance contracts	—		50,351			—		50,351
Corporate bonds	—		54,207			—		54,207
Asset-backed securities	—		3,619			—		3,619
Mortgage-backed securities	—		11,250			—		11,250
Commingled funds	—		282,378			—		282,378
Other	—		(1,841		)	—		(1,841		)
Total	$	26,324	$	448,734		$	—	$	475,058


^(a)	Includes restricted cash of $1.0 million at Dec. 31, 2014.

For the years ended Dec. 31, 2015 and 2014 there were no assets transferred in or out of Level 3. The following table presents the changes in Xcel Energy’s Level 3 postretirement benefit plan assets for the year ended Dec. 31, 2013:



(Thousands of Dollars)	Jan. 1, 2013		Net Realized Gains (Losses)		Net Unrealized Gains (Losses)		Purchases, Issuances and Settlements, Net		Transfers Out of Level 3 ^(a)			Dec. 31, 2013
Private equity investments	$	757	$	—	$	—	$	—	$	(757	)	$	—
Real estate	39,958		—		—		—		(39,958		)	—
Total	$	40,715	$	—	$	—	$	—	$	(40,715	)	$	—


^(a)	Transfers out of Level 3 into Level 2 were principally due to diminished use of unobservable inputs that were previously significant to these fair value measurements and were subsequently sold during 2013.

Benefit Obligations — A comparison of the actuarially computed benefit obligation and plan assets for Xcel Energy is presented in the following table:



(Thousands of Dollars)	2015			2014
Change in Projected Benefit Obligation:
Obligation at Jan. 1	$	642,869		$	731,428
Service cost	2,116			3,457
Interest cost	25,297			34,028
Medicare subsidy reimbursements	1,958			1,861
Plan participants’ contributions	6,718			7,148
Actuarial gain	(45,793		)	(81,699		)
Benefit payments	(48,898		)	(53,354		)
Obligation at Dec. 31	$	584,267		$	642,869



(Thousands of Dollars)	2015			2014
Change in Fair Value of Plan Assets:
Fair value of plan assets at Jan. 1	$	475,058		$	492,036
Actual (loss) return on plan assets	(3,570		)	12,083
Plan participants’ contributions	6,718			7,148
Employer contributions	18,325			17,145
Benefit payments	(48,898		)	(53,354		)
Fair value of plan assets at Dec. 31	$	447,633		$	475,058



(Thousands of Dollars)	2015			2014
Funded Status of Plans at Dec. 31:
Funded status	$	(136,634	)	$	(167,811	)
Noncurrent assets	1,820			1,014
Current liabilities	(7,495		)	(9,110		)
Noncurrent liabilities	(130,959		)	(159,715		)
Net postretirement amounts recognized on consolidated balance sheets	$	(136,634	)	$	(167,811	)



(Thousands of Dollars)	2015			2014
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost:
Net loss	$	103,039		$	124,064
Prior service credit	(64,925		)	(75,610		)
Total	$	38,114		$	48,454



(Thousands of Dollars)	2015			2014
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost Have Been Recorded as Follows Based Upon Expected Recovery in Rates:
Current regulatory assets	$	352		$	285
Noncurrent regulatory assets	50,135			59,697
Current regulatory liabilities	(985		)	(892		)
Noncurrent regulatory liabilities	(16,916		)	(17,216		)
Deferred income taxes	2,148			2,559
Net-of-tax accumulated OCI	3,380			4,021
Total	$	38,114		$	48,454



Measurement date	Dec. 31, 2015	Dec. 31, 2014



	2015		2014
Significant Assumptions Used to Measure Benefit Obligations:
Discount rate for year-end valuation	4.65	%	4.08	%
Mortality table	RP 2014		RP 2014
Health care costs trend rate — initial	6.00	%	6.50	%

Effective Jan. 1, 2016, the initial medical trend rate was decreased from 6.5 percent to 6.0 percent. The ultimate trend assumption remained at 4.5 percent. The period until the ultimate rate is reached is three years. Xcel Energy bases its medical trend assumption on the long-term cost inflation expected in the health care market, considering the levels projected and recommended by industry experts, as well as recent actual medical cost increases experienced by Xcel Energy’s retiree medical plan.

A one-percent change in the assumed health care cost trend rate would have the following effects on Xcel Energy:



	One-Percentage Point
(Thousands of Dollars)	Increase		Decrease
APBO	$	56,383	$	(47,972	)
Service and interest components	3,113		(2,594		)

Cash Flows — The postretirement health care plans have no funding requirements under income tax and other retirement-related regulations other than fulfilling benefit payment obligations, when claims are presented and approved under the plans. Additional cash funding requirements are prescribed by certain state and federal rate regulatory authorities. Xcel Energy contributed $18.3 million during 2015, $17.1 million during 2014, $17.6 million during 2013 and expects to contribute approximately $12.3 million during 2016.

Plan Amendments — In 2015 and 2014, there were no plan amendments made which affected the benefit obligation.

Benefit Costs — The components of Xcel Energy’s net periodic postretirement benefit costs were:



(Thousands of Dollars)	2015			2014			2013
Service cost	$	2,116		$	3,457		$	4,079
Interest cost	25,297			34,028			32,141
Expected return on plan assets	(26,600		)	(33,954		)	(33,011		)
Amortization of transition obligation	—			—			825
Amortization of prior service credit	(10,686		)	(10,688		)	(12,501		)
Amortization of net loss	5,404			11,740			22,325
Net periodic postretirement benefit cost	$	(4,469	)	$	4,583		$	13,858



	2015		2014		2013
Significant Assumptions Used to Measure Costs:
Discount rate	4.08	%	4.82	%	4.10	%
Expected average long-term rate of return on assets	5.80		7.17		7.11

Projected Benefit Payments

The following table lists Xcel Energy’s projected benefit payments for the pension and postretirement benefit plans:



(Thousands of Dollars)	Projected Pension Benefit Payments		Gross Projected Postretirement Health Care Benefit Payments		Expected Medicare Part D Subsidies		Net Projected Postretirement Health Care Benefit Payments
2016	$	260,240	$	48,047	$	2,355	$	45,692
2017	255,206		47,460		2,493		44,967
2018	263,689		47,039		2,637		44,402
2019	268,975		46,522		2,761		43,761
2020	271,853		46,819		2,869		43,950
2021-2025	1,353,351		220,122		16,053		204,069

Multiemployer Plans

NSP-Minnesota and NSP-Wisconsin each contribute to several union multiemployer pension and other postretirement benefit plans, none of which are individually significant. These plans provide pension and postretirement health care benefits to certain union employees, including electrical workers, boilermakers, and other construction and facilities workers who may perform services for more than one employer during a given period and do not participate in the NSP-Minnesota and NSP-Wisconsin sponsored pension and postretirement health care plans. Contributing to these types of plans creates risk that differs from providing benefits under NSP-Minnesota and NSP-Wisconsin sponsored plans, in that if another participating employer ceases to contribute to a multiemployer plan, additional unfunded obligations may need to be funded over time by remaining participating employers.

Contributions to multiemployer plans were as follows for the years ended Dec. 31, 2015, 2014 and 2013. The average number of NSP-Minnesota union employees covered by the multiemployer pension plans decreased to approximately 900 in 2015 from approximately 1,000 in 2014. There were no other significant changes to the nature or magnitude of the participation of NSP-Minnesota and NSP-Wisconsin in multiemployer plans for the years presented:



(Thousands of Dollars)	2015		2014		2013
Multiemployer pension contributions:
NSP-Minnesota	$	17,223	$	20,254	$	23,515
NSP-Wisconsin	944		156		130
Total	$	18,167	$	20,410	$	23,645
Multiemployer other postretirement benefit contributions:
NSP-Minnesota	$	135	$	273	$	390
Total	$	135	$	273	$	390