COSTCO DEFERRED COMPENSATION PLAN Amended and Restated September 8,2008 Article 1 Introduction

Exhibit 10.5

COSTCO DEFERRED COMPENSATION PLAN

Amended and Restated September 8, 2008

Article 1 – Introduction

This deferred compensation plan was established by Costco Wholesale Corporation, a Washington corporation (“Costco”), on January 30, 1990, and has been amended and restated from time to time. This is the restated Plan on September 8, 2008, which is intended to conform with section 409A of the Internal Revenue Code (“Code”). The purpose of this plan is to provide flexibility in timing the receipt of compensation to a select group of management and highly compensated employees.

Article 2 – Definitions

Whenever used in this plan, the following terms shall have the meanings set out below, unless the context clearly indicates otherwise. When the defined meaning is intended, the term is capitalized.

Article 3 – Eligibility and Selection of Participants

Eligibility shall be limited to a select group of management or highly compensated employees as designated by the Company for each year. Eligibility for participation in the Plan may change from year to year, depending on an employee’s position within the Company or on any other factors at the sole discretion of the Company. A Participant who is removed from the eligibility list due to demotion to a position or a salary level that is not eligible for participation shall continue to participate with respect to the deferrals already made under the Plan, including deferrals of Prior Deferred Compensation, but the Participant’s compensation after the demotion shall not be eligible for deferral hereunder until the Participant is re-designated in the eligibility list.

Article 4 – Election to Defer

Article 5 – Company Matching Credit

Vesting applies to each year’s matching credit on a separate, “class year” basis. Thus, five years after a Participant’s matching contribution is first credited in connection with the Participant’s first deferral, the Participant will be 100% vested in that first year’s matching credit, but not in the matching credits posted for deferrals in subsequent years, which vest separately according to the number of years that pass from the time of each deferral. Notwithstanding the foregoing, matching credits may be forfeited and the vested portion of a Participant’s matching Accounts may be decreased in the event of a hardship distribution of the deferrals to which the matching credits relate, under the terms set forth in Article 9.

A Participant must remain employed by the Company on the vesting date in order to be entitled to vesting credits on any January 1. However, a Participant shall become 100% vested in all Company matching credits, regardless of the class year vesting that would otherwise apply, in the following events:

Article 6 – Timing and Manner of Distribution

If a Participant fails to specify one of the payment options described above, such Participant shall be deemed to have specified the single lump sum payment option payable five years after the calendar year during which the compensation would have been paid, were it not deferred. If a Participant elects installment payments, the amount of any given installment shall be determined by dividing the then-current value of the Account by the remaining number of unpaid installments.

The minimum period of deferral is five years. For example, if funds were deferred from income otherwise payable in calendar year 1995, the earliest a lump sum payment or installment payment can be made from those particular funds would be in the first calendar quarter of the year 2000. However, distribution will be made earlier if a Participant dies, becomes totally disabled (as determined in accordance with Section 6.5), or Terminates Employment with the Company before reaching the age of 65, in the case of deferrals made before 1997, or before earning 65 “Vesting Points” while employed by the Company, in the case of deferrals made on or after January 1, 1997 (in accordance with Section 6.3).

Article 7 – Interest Credits

Article 8 – Rights of Participants and Funding

Article 9 – Hardship Payments

In order to qualify under this section, the hardship must be the result of an unforeseeable emergency. For this purpose, an “unforeseeable emergency” is an event or circumstance

described under Treas. Reg. section 1.409A-3(i)(3), i.e., an extraordinary and unanticipated emergency that is caused by an event beyond the control of the Participant (such as an illness, accident, casualty or other similar extraordinary and unforeseeable event) and that would result in severe financial hardship to the Participant if the early payment were not permitted. The Participant must supply written evidence of the financial hardship and must declare, under penalty of perjury, that the Participant has no other resources available to meet the emergency, including the resources of the Participant’s spouse and minor children that are reasonably available to the Participant. The Participant must also declare that the need cannot be met by any of the following:

The Committee may delegate decision-making authority hereunder to an independent person who may or may not be an employee of the Company.

For example, assume that a deferral of $12,000 was made in 1995, which entitled a Participant to a matching credit of $5,000 on January 1 of 1996. Assume also that the Participant receives a hardship payment of $6,000 in June of 1997, when the matching Account is 40% vested (in the apparent amount of $2,000). The first $2,000 of the hardship payment will be deemed to have been taken from deferrals not subject to the match. However, the remaining $4,000 of the payment results in a forfeiture of $2,000 of the matching credit in the Account and of any related interest credits. Ignoring interest credits for purposes of illustration, the $3,000 remaining matching credit remains 40% vested, which results in a revised vested amount of $1,200.

Article 10 – Administration

Amendments to the Plan, including termination of the Plan, shall be valid upon execution by any four members of the Committee, and no formal approval by the Board of Directors of the Company shall be required. However, the Company may also amend or terminate the Plan by resolution of the Board of Directors or an appropriate subcommittee thereof, and such amendment or termination supersedes any inconsistent action by the Committee, except as provided in Section 10.4, relating to a Change of Control of the Company.

Article 11 – Claims Procedure

The claimant may submit a written statement, documents, records, and other information. The claimant may also, free of charge upon request, have reasonable access to and copies of Relevant Documents. The review will consider all statements, documents, and other information submitted by the claimant, whether or not such information was submitted or considered under the initial denial decision. Claim determinations are made in accordance with Plan documents and, where appropriate, Plan provisions are applied consistently to similarly situated claimants.

The decision by the Committee on review shall be final and binding upon the claimant and all persons claiming by, through, or under the claimant, subject to the right to appeal under applicable law.

Article 12 – Code Section 409A Savings Clause

It is the intention of the Company that deferrals of compensation under this Plan shall comply in all respects with Code section 409A. Should it be determined that any provision or feature of the Plan is not in compliance with Code section 409A, that provision or feature shall be null and void to the extent required to avoid the noncompliance with Code section 409A. To the extent taxation of a Participant is required under Code section 409A, the Participant’s Account shall be distributed to the Participant in an amount equal to the amount required to be included in income under Code section 409A less any required income and payroll tax withholdings under Federal, state, local or other tax laws.

Article 13 – Miscellaneous