BlueLinx Holdings Inc.

BLUELINX HOLDINGS INC.

1950 Spectrum Circle, Suite 300

Marietta, Georgia 30067

770-953-7000

GENERAL INFORMATION

Why did I receive this proxy statement?

This proxy statement is furnished in connection with the solicitation of proxies on behalf of our Board of Directors (the “Board”) to be voted at the Annual Meeting of our stockholders to be held on May 14, 2026, and any adjournment or postponement thereof, for the purposes set forth in the accompanying “Notice of Annual Meeting of Stockholders.” The meeting will be held at BlueLinx’s corporate headquarters, 1950 Spectrum Circle, Suite 300, Marietta, Georgia 30067, on Thursday, May 14, 2026, at 11:00 a.m. Eastern Time. This proxy statement and accompanying proxy card are being first sent or provided to our stockholders on or about April 9, 2026. Our Form 10-K for the fiscal year ended January 3, 2026, including the financial statements and a list of exhibits, accompanies this proxy statement, as part of our 2025 Annual Report.

We encourage you to vote your shares prior to the Annual Meeting.

Who is soliciting my vote?

Our Board is soliciting your vote at the 2026 Annual Meeting of Stockholders of BlueLinx Holdings Inc.

Who is entitled to vote?

Only our stockholders of record at the close of business on Friday, March 20, 2026, the “Record Date,” are entitled to receive notice of the meeting, attend the meeting and vote the shares of our common stock held by each stockholder on that date at the meeting, or any adjournment or postponement thereof. Each outstanding share that you own as of the Record Date entitles you to cast one vote on each matter to be voted upon.

Who can attend the meeting?

Only stockholders of record as of the close of business on the Record Date, or their duly appointed proxies, may attend the meeting. Each stockholder who attends the meeting may be asked to present valid government-issued picture identification, such as a driver’s license or passport.

Please note that if you hold your shares in “street name” (that is, through a broker or other nominee), to attend the meeting you will need to present an original or copy of an official and authentic brokerage statement reflecting your stock ownership as of the Record Date. If you are a stockholder of record, your name will appear on our stockholder list.

What will I vote on?

Four items:

•the election of nine directors to our Board;

•the ratification of Ernst & Young LLP as our independent registered public accounting firm for fiscal 2026;

•a non-binding, advisory vote to approve the executive compensation described in this proxy statement; and

•an amendment to the BlueLinx Holdings Inc. 2021 Long-Term Incentive Plan (the "2021 Plan") to increase the number of shares of common stock reserved for issuance under the 2021 Plan.

Will there be any other items of business on the agenda?

We do not expect any other items of business at the meeting. Nonetheless, if an unforeseen matter is raised, your proxy will give discretionary authority to the persons named on the proxy to vote on any other matters that may be brought before the meeting.

How many votes must be present to conduct business at the meeting?

The presence at the meeting, in person or by proxy, of the holders of a majority of the shares of our common stock outstanding on the Record Date will constitute a quorum permitting business to be conducted at the annual meeting. As of the Record Date, we had 7,867,196 shares of common stock outstanding. Proxies received but marked as abstentions or broker non-votes will be included in the calculation of the number of shares considered to be present at the meeting. A broker non-vote occurs when a nominee holding shares for a beneficial owner does not vote on a particular proposal because the nominee does not have discretionary voting power with respect to that item and has not received voting instructions from the beneficial owner.

How do I vote?

You may vote by timely and properly completing and signing the accompanying proxy card and returning it to us. If you are a registered stockholder and attend the meeting, you may deliver your completed proxy card in person. “Street name” stockholders who wish to vote at the meeting will need to obtain a proxy form from the institution that holds their shares and complete and return that proxy in accordance with the instructions therein.

Can I change my vote after I return my proxy card?

Yes. Even after you have submitted your proxy, you may change your vote at any time before the proxy is exercised by filing either a notice of revocation, or a duly executed proxy bearing a later date, with our Corporate Secretary, at our principal executive offices: BlueLinx Holdings Inc., Attn: General Counsel & Corporate Secretary, 1950 Spectrum Circle, Suite 300, Marietta, Georgia 30067. The powers of the proxy holder(s) will be suspended if you attend the meeting in person and so request, although attendance at the meeting will not by itself revoke a previously granted proxy.

What are the recommendations of our Board of Directors?

Our Board recommends a vote FOR the election of each of the nine nominated directors, FOR the ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for fiscal 2026, FOR the approval of the executive compensation of the named executive officers described in this proxy statement, and FOR the amendment to the 2021 Plan.

What vote is required to approve each item?

Election of Directors. To be elected in an uncontested election, such as this one, a director nominee must receive a majority of the votes cast with respect to that director at the meeting. Any nominee who is serving as a director (an incumbent) and does not receive a majority of the votes cast with respect to that director, must submit an irrevocable offer of resignation for consideration by the Board. See “Majority Voting” below. Abstentions and broker non-votes are not counted as votes cast and will have no effect on the result of the vote for the election of directors.

Ratification of Independent Registered Public Accounting Firm. The affirmative vote of the holders of a majority of the shares present or represented by proxy and entitled to vote is required to ratify the appointment of Ernst & Young LLP as our independent registered public accounting firm for fiscal 2026. As a result, abstentions will have the effect of a vote “against” the proposal; however, broker non-votes will have no effect on this proposal. If our stockholders fail to ratify the selection, the Audit Committee may, but is not required to, reconsider whether to retain Ernst & Young LLP as our independent registered public accounting firm for fiscal 2026. Even if the selection is ratified, the Audit Committee, in its discretion, may direct the appointment of a different independent auditing firm at any time during the fiscal year if it determines that such a change would be in our best interests and that of our stockholders.

Approval on a non-binding, advisory basis, of the compensation of the Company’s named executive officers. Adoption of the resolution approving, on a non-binding, advisory basis, the compensation of the Company’s named executive officers, as disclosed in the Compensation

Discussion and Analysis section, compensation tables, and narrative discussion of this proxy statement, requires the affirmative vote of the holders of a majority of the shares present or represented by proxy and entitled to vote. As a result, abstentions will have the effect of a vote “against” the proposal; however, broker non- votes will have no effect on this proposal.

Approval of Amendment to the 2021 Plan. Approval of the amendment to the 2021 Plan requires the affirmative vote of the holders of a majority of the shares present or represented by proxy and entitled to vote. As a result, abstentions will have the effect of a vote “against” the proposal; however, broker non-votes will have no effect on this proposal.

What if I don’t vote for some or all of the matters listed on my proxy card?

If you are a registered stockholder and you return a signed proxy card without indicating your vote for some or all of the matters, your shares will be voted as follows for any matter you did not indicate a vote on:

•FOR the election of each of the director nominees to the Board listed on the proxy card;

•FOR the ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for fiscal 2026;

•FOR the approval, on an advisory, non-binding basis, of the executive compensation described in this proxy statement; and

•FORthe approval of the amendment to the 2021 Plan.

How will proxies be solicited?

Proxies will be solicited by mail. Proxies may also be solicited by our officers and regular employees personally or by telephone or facsimile, but such persons will not be specifically compensated for such services. Banks, brokers, nominees, and other custodians and fiduciaries will be reimbursed for their reasonable out-of-pocket expenses in forwarding soliciting material to their principals, the beneficial owners of our common stock. We will pay the expense of preparing, assembling, printing, mailing, and soliciting proxies.

Is there electronic access to the proxy materials and annual report?

Yes. The materials will be available, as of the date they were first mailed to our stockholders, by visiting www.proxyvote.com. In addition, this proxy statement and our Annual Report on Form 10-K are available on the Investor Relations page of our website at www.BlueLinxCo.com.