Form 8-K

8-K — Castellum, Inc.

Accession: 0001877939-26-000040

Filed: 2026-05-18

Period: 2026-05-18

CIK: 0001877939

SIC: 8742 (SERVICES-MANAGEMENT CONSULTING SERVICES)

Item: Regulation FD Disclosure

Item: Financial Statements and Exhibits

Documents

8-K — ctm-20260518.htm (Primary)

EX-99.1 (exhibit991may182026.htm)

EX-99.2 (exhibit992ctm-2026annual.htm)

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8-K

8-K (Primary)

Filename: ctm-20260518.htm · Sequence: 1

ctm-20260518

0001877939False00018779392026-05-182026-05-18

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities and Exchange Act of 1934

Date of Report (Date of earliest event reported): May 18, 2026

CASTELLUM, INC.

(Exact name of Registrant as specified in its charter)

Nevada 001-41526 27-4079982

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)

1934 Old Gallows Road, Suite 350

Vienna, VA 22182

(Address of principal executive offices, including zip code)

(703) 752-6157

(Registrant’s telephone number, including area code)

Check the appropriate box below if the 8-K filing is intended to simultaneously satisfy the filing obligations of the registrant under any of the following provisions:

☐ Written communication pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13(c)).

Securities registered pursuant to Section 12(b) of the Act:

Title of each class Trading Symbol(s) Name of each exchange on which registered

Common stock, par value $0.0001 per share CTM NYSE American LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☒

Item 7.01 Regulation FD Disclosure.

On May 18, 2026, Castellum, Inc. (the "Company") issued a press release announcing information concerning the 2026 Annual Stockholders Meeting (the "2026 Annual Meeting"), including details on how to access the presentation (the "Meeting Presentation") which will follow the adjournment of the 2026 Annual Meeting. The full text of the press release is attached hereto as Exhibit 99.1 and the Meeting Presentation is attached hereto as Exhibit 99.2, both of which are incorporated herein by reference.

The information in this Form 8-K and the Exhibits 99.1 and 99.2 attached hereto shall not be deemed “filed” for purposes of Section 18 of the Securities Act of 1934, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, except as shall be expressly set forth by specific reference.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No. Exhibit Title

99.1

Press Release dated May 18, 2026

99.2

2026 Annual Stockholders - Management Presentation

104 Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized.

CASTELLUM, INC.

Date: May 18, 2026 By: /s/ Glen R. Ives

Name: Glen R. Ives

Title: Chief Executive Officer (Principal Executive Officer)

EX-99.1

Filename: exhibit991may182026.htm · Sequence: 2

Document

Exhibit 99.1

Castellum Reminds Stockholders to Submit Their Vote at Its Upcoming 2026 Annual Meeting

To be Held on Tuesday, May 19, 2026 at 10:00 a.m. ET

VIENNA, Va., May 18, 2026 (GLOBE NEWSWIRE) – Castellum, Inc. (NYSE-American: CTM) (“Castellum” “CTM”, “we” or the “Company”), a cybersecurity, electronic warfare, and software services company focused on the federal government, today reminds stockholders that its 2026 Annual Meeting of Stockholders (“2026 Annual Meeting”) will be held on Tuesday, May 19, 2026 at 10:00 a.m. ET.

Stockholders of record at the close of business on March 20, 2026, as described in the Company’s previously distributed proxy materials, are entitled to attend and vote at the 2026 Annual Meeting and any adjournment or postponement thereof.

Stockholders can attend the 2026 Annual Meeting:

–In person at Intelligent Office, Tysons, 1934 Old Gallows Road, Room 362, Tysons, VA 22182; or,

–Virtually via a live audio webcast by dialing (800) 715-9871 or (646) 307-1963; conference identification number is 9842123.

Stockholders are encouraged to vote their shares in advance of the 2026 Annual Meeting by using one of the methods described in the proxy materials (internet, telephone or mail). Those who plan to attend in person or virtually should allow extra time for online check‑in, registration and any applicable security procedures before the 2026 Annual Meeting begins.

After the adjournment of the 2026 Annual Meeting, members of CTM's management will host a brief presentation, followed by a question-and-answer session. A copy of the presentation will be posted to the Company’s website under the “Investor” tab at https://investors.castellumus.com/events-and-presentations/default.aspx, before the start of the 2026 Annual Meeting.

Additional information regarding the 2026 Annual Meeting, including the agenda, the Company’s proxy statement and annual report, is available at www.sec.gov.

About Castellum, Inc.

Castellum, Inc. (NYSE-American: CTM) is a technology company focused on leveraging the power of information technology to help solve our Nation's most pressing national security challenges. CTM provides U.S. government and commercial clients with Cybersecurity, Software Development, Systems Engineering, Information / Electronic Warfare, Program Support, and Data Analytics services. It also

offers subject matter expertise in artificial intelligence / machine learning, 5G technologies, model-based systems engineering, program management, information assurance, intelligence analysis, and CMMC compliance. In addition to constantly innovating and enhancing its organic capabilities, Castellum is executing strategic acquisitions of firms that share our passionate commitment to U.S. national security and have a history of bringing exceptional value to their clients. For more information visit: https://castellumus.com.

Forward-Looking Statements:

This release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 2lE of the Securities Exchange Act of 1934, as amended. These forward-looking statements represent the Company's expectations or beliefs concerning future events and can generally be identified by the use of statements that include words such as "estimate," "project," "believe," "anticipate," "shooting to," "intend," "in a position," "looking to," "pursue," "positioned," "will," "likely," "would," or similar words or phrases. Forward-looking statements include, but are not limited to, statements regarding the Company's expectations for revenue growth, new customer opportunities, improvements to cost structure, and profitability. These forward-looking statements are subject to risks, uncertainties, and other factors, many of which are outside of the Company's control, that could cause actual results to differ (sometimes materially) from the results expressed or implied in the forward-looking statements, including, among others: the Company's ability to continue to grow and execute on its total backlog and qualified pipeline and compete against new and existing competitors; its ability to effectively integrate and grow its acquired companies; its ability to identify additional acquisition targets and close additional acquisitions; and the Company's ability to maintain the listing of its common stock on the NYSE American LLC. For a more detailed description of these and other risk factors, please refer to the Company's Annual Report on Form 10-K and its Quarterly Reports on Form 10-Q and other filings with the Securities and Exchange Commission ("SEC") which can be viewed at www.sec.gov. All forward-looking statements are inherently uncertain, based on current expectations and assumptions concerning future events or the future performance of the Company. Readers are cautioned not to place undue reliance on these forward-looking statements, which are only predictions and speak only as of the date hereof. The Company expressly disclaims any intent or obligation to update any of the forward-looking statements made in this release or in any of its SEC filings except as may be otherwise stated by the Company.

Contacts:

Castellum, Inc.

1934 Old Gallows Road, Suite 350

Vienna, VA 22182

Investor Relations:

The Equity Group

Lena Cati

(212) 836-9611

lcati@theequitygroup.com

Val Ferraro

(212) 836-9633

vferraro@theequitygroup.com

EX-99.2

Filename: exhibit992ctm-2026annual.htm · Sequence: 3

exhibit992ctm-2026annual

2026 Annual Meeting of Stockholders Presentation by Mr. Glen Ives, CEO May 19, 2026 NYSE-American: CTM

Cautionary Statement Concerning Forward-Looking Statements: This release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended and Section 21E of the Securities Exchange Act of 1934, as amended. These forward-looking statements represent the Company’s expectations or beliefs concerning future events and can generally be identified by the use of statements that include words such as “estimate,” “project,” “believe,” “anticipate,” “shooting to,” “intend,” “plan,” “foresee,” “likely,” “will,” “would,” “appears,” “goal,” “target” or similar words or phrases. Forward-looking statements include, but are not limited to, statements regarding the Company’s expectations for revenue growth and new customer opportunities, improvements to cost structure, and profitability. Forward-looking statements include, but are not limited to, statements regarding the Company’s expectations for revenue growth and new customer opportunities including opportunities arising from its contracts with NAVAIR and other customers, improvements to cost structure, and profitability. These forward-looking statements are subject to risks, uncertainties, and other factors, many of which are outside of the Company’s control, that could cause actual results to differ materially from the results expressed or implied in the forward-looking statements, including, among others: the Company’s ability to compete against new and existing competitors; its ability to effectively integrate and grow its acquired companies; its ability to identify additional acquisition targets and close additional acquisitions; the impact on the Company’s revenue due to a delay in the U.S. Congress approving a federal budget, operating under a prolonged continuing resolution, government shutdown, or breach of the debt ceiling, as well as the imposition by the U.S. government of sequestration in the absence of an approved budget; the ability of the U.S. federal government to unilaterally cancel a contract with or without cause, and more specifically, the potential impact of the U.S. DOGE Service Temporary Organization on government spending and terminating contracts for convenience; and the Company’s ability to maintain the listing of its common stock on the NYSE American LLC. For a more detailed description of these and other risk factors, please refer to the Company’s Annual Report on Form 10-K and its Quarterly Reports on Form 10-Q and other filings with the Securities and Exchange Commission (“SEC”) which can be viewed at www.sec.gov. All forward-looking statements are inherently uncertain, based on current expectations and assumptions concerning future events or future performance of the Company. Readers are cautioned not to place undue reliance on these forward-looking statements, which are only predictions and speak only as of the date hereof. The Company expressly disclaims any intent or obligation to update any of the forward-looking statements made in this release or in any of its SEC filings except as may be otherwise stated by the Company. Integrity. Innovation. Engagement. Sustainability. 2

• Castellum’s Evolution • Leadership • Castellum Today • Programs We Support • Contract Wins, Backlog & Pipeline • Key Financial Metrics • Growth Strategy • Performance Highlights • Questions • Contact Us • Appendix Agenda Integrity. Innovation. Engagement. Sustainability. 3

Castellum’s Evolution Integrity. Innovation. Engagement. Sustainability. Founded in 2019 Listed on NYSE American in Oct 2022 • Completed 7 acquisitions • Built and integrated a scalable public company platform • Focused on delivering leading-edge technology services & solutions • Built strong footprint within DoD, particularly Navy and Army Phase 1: BUILD PLATFORM & INTEGRATE Nov 2019 – Jul 2024 • Continue to strengthen organic growth momentum (Q1 2026: strong revenue growth and positive EBITDA) • Expand M&A strategy and execution • Leverage CMMC Level 2 C3PAO Certification • Further invest in mission technologies, capabilities and resources • Expand market and customer portfolio • Expand SBA mentorship protégé program Phase 2: ACCELERATE ORGANIC GROWTH Jul 2024 – Dec 2025 Phase 3: CONTINUE MOMENTUM & EXPAND Jan 2026 – Present • Record revenue and improved profitability • Three major prime contract wins, totaling nearly $220 million in value with five-year periods of performance • Record backlog provides strong forward visibility • Expanded and highly realistic pipeline of new opportunities • Strengthened leadership team with deep federal sector experience • Strong investment in BD, Capture, Proposal Development onboarding • Laser focused on markets where we have deep expertise 4

Strong and Proven Leadership Lieutenant General Bernard Champoux, USA (ret), Chair Mr. Mark Alarie General John Campbell, USA, (ret) Mr. Glen Ives The Honorable C. Thomas McMillen Glen Ives, President & CEO David Bell, CFO & Treasurer Andrew Merriman, COO Tammy Martin, General Counsel & Secretary Board of DirectorsExecutive Leadership and Management Integrity. Innovation. Engagement. Sustainability. Led by Highly Experience Management Team and Board 5

Castellum Today Relevant, powerful, high demand technologies and mission capabilities: Integrity. Innovation. Engagement. Sustainability. Subsidiaries: 6

Aircraft Launch and Recovery (ALRE) Integrity. Innovation. Engagement. Sustainability. Programs We Support Integrated Fresnel Lens Optical Landing System (IFLOLS) Augmented Reality Maintenance System (ARMS) / XRa PMA-290 P-8 Poseidon Special Projects 7

Integrity. Innovation. Engagement. Sustainability. Programs We Support (cont.) Model Based System Engineering Data Analytics Electronic WarfareCyber Security and Warfare 8

Backlog, Pipeline and Contract Momentum Contract Backlog * $273.3M vs $265M at 12/31/25 Integrity. Innovation. Engagement. Sustainability. Contract Backlog is defined as the total value of work remaining to be performed on awarded government contracts, including both funded and unfunded portions. The Opportunity Pipeline represents the revenue opportunity for the Company from potential future contracts obtained through organic growth from qualified customers based on the expected base year contract value plus the value of all option periods. Opportunity Pipeline * $938M vs $817M at 12/31/25 Top three revenue-producing contracts 2025 Contract Wins $219M+ 5+ year runway Entered 2026 on a very strong note: * As of 3/31/2026 9

Historical Key Financial Metrics Integrity. Innovation. Engagement. Sustainability. Debt-Free Balance Sheet Strong cash position of ~$15.8M at 3/31/26; eliminated all debt in early 2026, reducing financial risk 1.4 13.3 25.1 42.2 45.3 44.8 52.9 14.3 0 10 20 30 40 50 60 2019 2020 2021 2022 2023 2024 2025 Q1 2026 Revenue ($ in millions) 0.3 6.2 11.1 17.6 18.7 18.3 19.4 5.1 0 5 10 15 20 25 2019 2020 2021 2022 2023 2024 2025 Q1 2026 Gross Profit ($ in millions) 0.2 0.8 1.0 0.4 0 0.2 0.4 0.6 0.8 1 1.2 2023 2024 2025 Q1 2026 Adj EBITDA ($ in millions) Adj EBITDA metric reported following Castellum’s uplisting on the NYSE American (see reconciliation table on slide 17) 10 Q1 2026 was CTM’s best first quarter ever and second best of any quarter on record in terms of revenue Gross profit and gross margin fluctuate based on contract mix and type

Growth Strategy Integrity. Innovation. Engagement. Sustainability. ORGANIC EXPANSION: Driving Revenue Growth and Improve Margins Drive revenue growth by wining new prime contracts and task ordersFocus Integrate and promote cross selling between subsidiaries to unlock efficiencies, and new contract opportunitiesBuild Presence across all DoD branches and geographiesExpand R&D focused on AR solutions, cyber supply chain risk, to launch innovative offerings and core capabilities in AI/ML, C5ISR, Electronic Warfare, and Digital ModernizationDevelop With advanced tech firms (Autonomous Systems, UAV/counter-UAV, AI/ Data Analytics)Partner Scale the business to achieve optimal operating margins and shareholder returnsGoal 11

Growth Strategy (cont.) Selective, accretive acquisitions that expand core capabilitiesFocus Companies with strong existing federal prime contracts and recurring revenueTarget Companies with cultural and operational fit to enable seamless integrationPrioritize Acquisitions to enter in new markets or deepen presence in key agencies (e.g., DoD, Navy, AirForce, Intelligence Community)Use Disciplined approach to valuation and deal structure to protect shareholder valueMaintain Acquisitions to establish synergies and margin improvementIntegrate ACQUISITION STRATEGY: Adding Scale and Capabilities Integrity. Innovation. Engagement. Sustainability. 12

Performance Highlights Integrity. Innovation. Engagement. Sustainability. Positioned to deliver shareholder value through disciplined execution and organic growth. 13 Record Backlog and Robust Pipeline Defense focused and federal IT & cybersecurity platform positioned to perform through budget cycles and administration changes Demonstrate strong demand and solid execution Through scale and operating leverage Provides increased financial flexibilityProvide strong visibility for 2026 Aims to increase scale and expand offeringsWith proven execution track record Record Revenue & Contract Wins Seeking Accretive M&As Debt Free Balance Sheet Clear Path to Profitability Highly Resilient Business Led by Experienced Team

Questions Integrity. Innovation. Engagement. Sustainability. 14 Questions?

Contact Us Integrity. Innovation. Engagement. Sustainability. 15 Castellum. Inc. 1934 Old Gallows Rd, Suite 350 Vienna, VA 22182 (703) 752-6157 Investor Relations The Equity Group Lena Cati (212) 836-9611 lcati@theequitygroup.com Val Ferraro (212) 836-9633 vferraro@theequitygroup.com

Appendix Integrity. Innovation. Engagement. Sustainability. 16

Appendix Integrity. Innovation. Engagement. Sustainability. 17 March 31, 2026 December 31, 2025 (unaudited) Assets Current Assets: Cash $ 15,772,974 $ 14,884,778 Accounts receivable, net 7,714,969 8,180,180 Contract asset 541,441 568,705 Due from buyer 57,049 58,207 Prepaid income taxes 146,245 153,153 Prepaid expenses and other current assets 764,894 800,671 Total current assets 24,997,572 24,645,694 Fixed assets, net 220,419 231,136 Non-Current Assets: Due from buyer, net of current portion 44,371 77,259 Right of use asset - operating lease 718,137 800,069 Investment in joint ventures/captive insurance entity 100,250 100,250 Intangible assets, net 5,067,056 5,371,602 Goodwill 10,676,834 10,676,834 Total non-current assets 16,827,067 17,257,150 Total Assets $ 41,824,639 $ 41,902,844 March 31, 2026 December 31, 2025 (unaudited) Liabilities and Stockholders' Equity Liabilities Current Liabilities Accounts payable and accrued expenses $ 1,981,584 $ 1,904,962 Accrued payroll and payroll related expenses 2,952,153 2,761,998 Current portion of lease liability – operating leases 251,073 270,868 Derivative liability 10,000 262,000 Notes payable, related party — 400,000 Total current liabilities 5,194,810 5,599,828 Non-Current Liabilities Lease liability – operating leases, net of current portion 487,188 550,219 Total non-current liabilities 487,188 550,219 Total Liabilities $ 5,681,998 $ 6,150,047 Stockholders' Equity Preferred stock, 50,000,000 shares authorized Series A Preferred stock, par value $0.0001; 10,000,000 shares authorized; 5,875,000 issued and outstanding as of March 31, 2026 and December 31, 2025, respectively 588 588 Series C Preferred stock, par value $0.0001; 10,000,000 shares authorized; 570,000 and 570,000 issued and outstanding as of March 31, 2026 and December 31, 2025, respectively 57 57 Common stock, par value, $0.0001, 3,000,000,000 shares authorized, 94,612,750 and 94,612,750 issued and outstanding as of March 31, 2026 and December 31, 2025, respectively 9,461 9,461 Additional paid in capital 93,098,846 92,330,909 Accumulated deficit (56,966,311) (56,588,218) Total stockholders' equity 36,142,641 35,752,797 Total Liabilities and Stockholders' Equity $ 41,824,639 $ 41,902,844 Consolidated Balance Sheet

Integrity. Innovation. Engagement. Sustainability. 18 Three Months Ended March 31, 2026 2025 Revenues $ 14,291,961 $ 11,664,365 Cost of Revenues 9,229,741 7,109,749 Gross Profit 5,062,220 4,554,616 Operating Expenses Indirect costs 2,461,140 2,385,544 Overhead 644,356 512,924 General and administrative 2,654,722 3,142,155 Total operating expenses 5,760,218 6,040,623 Loss From Operations Before Other Income (697,998) (1,486,007) Other Income (Expense) Gain from change in fair value of derivative liability 252,000 501,000 Interest income (expense), net 101,400 (110,764) Total other income 353,400 390,236 Loss Before Income Taxes and Preferred Stock Dividends (344,598) (1,095,771) Income tax benefit (expense) (6,676) (74,276) Net Loss (351,274) (1,170,047) Less: preferred stock dividends 26,819 26,984 Net Loss To Common Shareholders $ (378,093) $ (1,197,031) Net Loss Per Share - Basic And Diluted $ 0.00 $ (0.01) Weighted Average Shares Outstanding - Basic And Diluted 94,612,750 80,953,373 Consolidated Statement of Operations Appendix (cont.)

Integrity. Innovation. Engagement. Sustainability. Three Months Ended March 31, 2026 2025 Revenues $ 14,291,961 $ 11,664,365 Gross profit 5,062,221 4,554,616 Loss from operations before other income (expense) (697,998) (1,482,366) Add Back: Depreciation and amortization 324,991 378,187 Adjust for non-cash and one-time charges Stock based compensation 767,937 1,179,209 Non-recurring charges - - Total non-cash charges 767,937 1,179,209 Non-GAAP Adjusted EBITDA $ 394,930 $ 75,030 19 Reconciliation of Non-GAAP Adjusted EBITDA Appendix (cont.)

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Name of the City or Town

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Code for the postal or zip code

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Name of the state or province.

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A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

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-Publisher SEC

-Name Exchange Act

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Indicate if registrant meets the emerging growth company criteria.

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Indicate if an emerging growth company has elected not to use the extended transition period for complying with any new or revised financial accounting standards.

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-Publisher SEC

-Name Securities Act

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-Subsection 2

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- Definition

Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

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No definition available.

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Two-character EDGAR code representing the state or country of incorporation.

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The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

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-Publisher SEC

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-Number 240

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The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

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Local phone number for entity.

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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act.

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-Section 13e

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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act.

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- Definition

Title of a 12(b) registered security.

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Name of the Exchange on which a security is registered.

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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as soliciting material pursuant to Rule 14a-12 under the Exchange Act.

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Trading symbol of an instrument as listed on an exchange.

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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as written communications pursuant to Rule 425 under the Securities Act.

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