Form 8-K

8-K — HARVARD BIOSCIENCE INC

Accession: 0001171843-26-003271

Filed: 2026-05-12

Period: 2026-05-12

CIK: 0001123494

SIC: 3826 (LABORATORY ANALYTICAL INSTRUMENTS)

Item: Regulation FD Disclosure

Item: Financial Statements and Exhibits

Documents

8-K — f8k_051226.htm (Primary)

EX-99.1 — EXHIBIT 99.1 (exh_991.htm)

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2026-05-12

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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 Exchange Act of 1934

Date of Report (Date of earliest event reported): May 12, 2026

HARVARD BIOSCIENCE, INC.

(Exact name of registrant as specified in its charter)

Delaware

001-33957

04-3306140

(State or Other Jurisdiction of Incorporation)

(Commission File Number)

(I.R.S. Employer Identification No.)

84 October Hill Road

Holliston, MA 01746

(Address of Principal Executive Offices) (Zip Code)

(508) 893-8999

(Registrant's telephone number, including area code)

(Former name or former address, if changed since last report)

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

☐

Written communications 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 240.13e-4(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, $0.01 par value

HBIO

The NASDAQ Capital Market

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

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.

Corporate Presentation

The Company from time to time presents and/or distributes to the investment community at various industry and other conferences slide presentations to provide updates and summaries of its business. A copy of the Company’s current corporate slide presentation is attached hereto as Exhibit 99.1 and incorporated herein by reference.

The information in Item 7.01 of this Current Report on Form 8-K, including Exhibit 99.1 attached hereto, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

EXHIBIT

NUMBER

EXHIBIT DESCRIPTION

99.1

Corporate slide presentation of Harvard Bioscience, Inc., dated May 2026.

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.

HARVARD BIOSCIENCE, INC.

Date: May 12, 2026

By:

/s/ Mark Frost

Mark Frost

Chief Financial Officer

EX-99.1 — EXHIBIT 99.1

EX-99.1

Filename: exh_991.htm · Sequence: 2

Exhibit 99.1

NASDAQ: HBIO Harvard Bioscience Investor Overview May 2026

Forward - Looking Statements & Non - GAAP Financial Information Forward Looking Statements This document contains forward - looking statements within the meaning of the federal securities laws, including the Private Securities Litigation Reform Act of 1995. Forward - looking statements may be identified by the use of words such as “may,” “will,” “expect,” “plan,” “anticipate,” “estimate,” “intend” and similar expressions or statements that do not relate to historical matters. Forward - looking statements include, but are not limited to, information concerning expected future financial and operational performance including revenues, gross margins, adjusted EBITDA and EBITDA margin, cash and debt position, growth and the introduction of new products, and the strength of the Company’s market position and business model and anticipated macroeconomic conditions. Forward - looking statements are not guarantees of future performance and involve known and unknown uncertainties, risks, assumptions, and contingencies, many of which are outside the Company’s control. Risks and other factors that could cause the Company’s actual results to differ materially from those described its forward - looking statements include those described in the “Risk Factors” section of the Company’s most recently filed Annual Report on Form 10 - K as well as in the Company’s other filings with the Securities and Exchange Commission. Forward - looking statements are based on the Company’s expectations and assumptions as of the date of this document. Except as required by law, the Company assumes no obligation to update forward - looking statements to reflect any change in expectations, even as new information becomes available. Use of Non - GAAP Financial Information This document contains non - GAAP financial information, including one or more of adjusted operating income (loss), adjusted operating margin, adjusted net income (loss), adjusted EBITDA, adjusted EBITDA margin, diluted adjusted earnings (loss) per share, and net debt. We believe that this non - GAAP financial information provides investors with an enhanced understanding of the underlying operations of our business. For the periods presented, these non - GAAP financial measures have excluded certain expenses and income resulting from items that we do not believe are representative of the underlying operations of the business. Items excluded include stock - based compensation, amortization of intangibles related to acquisitions, other operating expenses, goodwill impairment, interest and other expenses, net, loss on pension settlement, loss on equity securities, income taxes, and the tax impact of reconciling items. Management believes that this non - GAAP financial information is important in comparing current results with prior period results and is useful to investors and financial analysts in assessing the Company’s operating performance. Historical non - GAAP financial information included herein is accompanied by a reconciliation to the nearest corresponding GAAP measure, which is included below. With respect to non - GAAP forward - looking measures, we provide an outlook for adjusted EBITDA margin. Many of the items that we exclude from this forward - looking measure calculation may not be subject to the control of or may not be reliably predicted by management. These items could cause our non - GAAP forward looking measures to vary materially from measures reported under GAAP. The non - GAAP financial information provided in this document should be considered in addition to, not as a substitute for, the financial information provided and presented in accordance with GAAP and may be different than other companies’ non - GAAP financial information. 2

“Accelerating drug development through human - relevant translational tools” Vision 3

Harvard Bioscience By The Numbers 54% Recurring Revenue (path to 60%+) #1 or #2 in 7 of 10 product lines 10,000+ Customers $87M Revenue FY25 Guiding 2 - 4% growth in FY26 4 58% Adj. Gross Margin FY25 Guiding 58 - 60% in FY26 $8M Adj. EBITDA FY25 Guiding 6 - 10% growth in FY26 Harvard Bioscience builds tools that power translational research across drug discovery & preclinical development FY25 revenue more than 1.5x company enterprise value* *Enterprise value as of 3/13/26

Recent Actions New Executive Leadership: Appointed John Duke CEO effective July 2025 & made Mark Frost permanent CFO in March of 2026 Expanded Board of Directors: Appointed Rob Gagnon & Seth Benson effective July 2025, Stephen DeNelsky effective September 2025, BroadOak Partner Bill Snider effective December 2025 Focused Strategic Direction: Announced focus on Translational Science products in February 2026 Debt Refinancing: Extended debt maturity to 2029, reduced annual debt service generating $3 million in annual cash savings, & enhanced financial flexibility to support long term growth objectives & BroadOak made $7.5M investment in convertible notes Strategic Consolidation: Streamlining production footprint & improving manufacturing efficiency through phased closure of Holliston, MA plant – expected to deliver approximately $3 million of adjusted EBITDA improvement in 2027 and $4 million of improvement beginning in 2028

Debt Refinancing: $40M Deal Structure Note: Shares & share price adjusted to account for reverse split 6 BroadOak Conversions Exit Fee Prepayment Penalty Amortization Maturity Interest Rate Amount Term Loan BroadOak received warrants for 200K shares at $5.00/share Right to nominate one board member while loans remain outstanding (BroadOak partner Bill Snider nominated) Can be converted to ABL providing lower interest rate, more flexibility, and reduction of Exit fee 10.00% exit fee on all prepaid or repaid amounts (including at maturity) Can be reduced by 50% on Term Loan A if Asset Based Loan (ABL) completed Year 1: 3.00% Year 2: 2.00% Year 3: 1.00% Year 4+: 0% No prepayment premium on Term A Loan prepaid before March 31 , 2027 Commencing December 31, 2027, the Company is required to make quarterly principal amortization payments The Amortization Date may be extended by one year if adjusted EBITDA milestone is achieved December 2029 Maturity may extend one year if adjusted EBITDA milestone is achieved Per annum rate: greater of (i) 12.80% (first 2 years), then 12.50%; (ii) or prime rate + 5.25% $10M A N/A $22.5M B Converts to common stock at $10.00/share (Jan 2, 2026 – maturity) Auto - converts if share price exceeds $15.00 for 30 consecutive trading days No exit fee on Term C Loan that converts into Common Stock Term C Loan may not be prepaid, except in the event of a repayment in full of all of the Term Loans or a change of control of the Company, in which case the Lenders may elect whether to convert their Term C Loans into Common Stock or to be repaid in full in cash. N/A $7.5M C Reduced annual debt service generating $3 million in annual cash savings

Project Viking: Strategic Manufacturing Consolidation Announced in Q1 2026 Expected completion in Q1 2027 $3M of cost savings directly contributing to Adj. EBITDA for FY 2027 $4M of cost savings directly contributing to Adj. EBITDA for FY 2028 and beyond ▪ Consolidating Holliston, MA manufacturing site over a 15 - month period, with expected completion by the end of 1Q27. ▪ All U.S. production will be based in Minneapolis, MN. ▪ Certain products will be consolidated to facilities in Germany, Sweden, and the U.K., to align specific product lines with their designated center of excellence. ▪ The Company is building surplus inventory to ensure no customer disruption. RELOCATION DETAILS 7

Investment Highlights: Strong Foundation Poised for Growth Market Leadership with Structural Tailwinds #1 preclinical telemetry franchise for 35+ years, & early organoid leadership Blue - Chip Customer Base Selling to diverse, blue - chip customer base on a global scale Recurring Revenue, High Margins & Positive Cash Flow Software, consumables, installed base drive visibility & margin expansion on products with high barrier to entry, generating increased cash for the Company Differentiated New Product Innovation (NPI) Pipeline MeshMEA , SoHo , Incub8 extend leadership into high - growth adjacencies New Management & BoD Refocused management team with deep experience supported by technically deep employee base & refreshed board of directors Strengthened Balance Sheet & Streamlined Operations 8 Refinancing & manufacturing consolidation unlock operating leverage

Key Strategic Pillars: The New Harvard Bioscience Historically known as life sciences tools company, becoming pure play Translational Science Tools company Positioning Company For Long - Term Growth Scale High - Margin Innovation Expand Recurring Revenue Mix Operate with Discipline Use preclinical cash flows to fund R&D, margin expansion, & bolt - ons Grow consumables, software, & services attached to installed base Advance differentiated NPI in telemetry, electrophysiology, & organoids Integrate in vivo telemetry with in vitro organoid platforms Lead the Translational Bridge 9

An Evolving Translational Science Market Regulatory, scientific, & economic shift in drug development ▪ Regulators usher in new tools : FDA, EMA, & other global regulators are actively pushing the adoption of New Approach Methodologies (NAMs) ▪ NAMs are human relevant technologies geared to reduce failure rates in drug discovery – currently, over 90% of drugs that pass animal trials fail in human trials ▪ Scientific tailwinds : NAMs have demonstrated a technical improvement in modeling biologic outcomes ▪ The FDA is encouraging submission of NAMs data, in addition to animal data, for new drug applications, which creates an additional market for our products ▪ Innovation continues : Next - gen organoid & 3D systems rapidly advance HBIO is uniquely positioned to lead during this transition ▪ Decades - long pre - clinical tools leadership : deep industry relationships with biopharma, CROs, regulators, & research institutions ▪ Workflow coverage : Products span across the translational science space from foundational tools to the latest NAM technologies (MeshMEA ) ▪ Installed advantage : Millions of products sold to thousands of customers around the globe & across the drug development ecosystem $10B+ Translational Tools Market 10

CELLULAR & MOLECULAR Boston PRECLINICAL SYSTEMS Minneapolis Core Operating Site Sales Office / Small Centers of Excellence *Headcount is approximate. Note: Headquarters moving to Minneapolis in 1Q27; Additional manufacturing sites in Sweden, Barcelona, and Freiburg 12 - 31 - 25 12 - 31 - 24 339 354 Employees* 10 10 Product Lines 8 8 Sites BIOPRODUCTION Cambridge, UK CELLULAR & MOLECULAR Stuttgart, Germany ▪ Strong commercial organization with 45 highly technical, deeply knowledgeable direct sales representatives ▪ Considerable manufacturing flexibility across five facilities adequately covers NA, EMEA, & Asia ▪ JD Edwards ERP system consolidation (completed in 2024) improved sales & operations planning ▪ Streamlining production footprint & improving manufacturing efficiency through phased closure of Holliston, MA plant A global operating platform with embedded growth leverage Global Footprint & Distribution – Built to Scale Efficiently 11

Why Who What ACADEMIC RESEARCH 50% of 2025 Revenue ▪ Scientific Research labs primarily government & grant funded ▪ Early discovery of new novel drugs & compounds for therapies & vaccines ▪ Advanced cellular testing & gene editing Breakthrough technologies & applications drive innovation BIOTECH, PHARMACEUTICAL 28% of 2025 Revenue ▪ Perform early discovery & then transition from discovery through preclinical regulatory & on to production ▪ Leverage discoveries from academics & biotech's ▪ Bridge to bio - production Reduced development cycle time drives BioPharma revenue growth Blue - Chip Customers Across Multiple Revenue Streams CONTRACT RESEARCH ORGANIZATIONS 22% of 2025 Revenue ▪ Preclinical studies to determine safety & efficacy of new pharmaceuticals ▪ Pharmaceutical companies are outsourcing significant preclinical activities to CROs Reduced test cycle - time drives CROs revenue growth Note: Logos reflects subset of blue - chip recurring customers. 12

Direct Sales 61% CHANNEL REVENUE MIX 2025 REVENUE BY SALES CHANNEL Distributors 39% SALES FORCE GEOGRAPHY 2025 SALES REPS BY REGION EMEA 38% AMERICAS 42% APAC 20% ▪ Effective direct sales channel supported by 45 highly technical, deeply knowledgeable direct sales representatives ▪ Global reach with strategic geographic mix based on sales & distribution footprint Direct Sales Force Complemented by Key Distributors for Global Reach 13 ▪ Signed Fisher North America agreement in August 2025, which increases customer access ▪ Working to sign similar agreement with another distributor in 2026, which would expand reach into large pharma

Research & Discovery Preclinical Safety & Toxicology CELLULAR TESTINGS COMPOUND CREATION CLINICAL SMALL MODEL SAFETY/TOXICOLOGY LARGE / NHP MODEL SAFETY/TOXICOLOGY Bio - Production Regulatory Report Low Yield ORGANOIDS LARGE POPULATION ▪ Leading provider of products across the drug development cycle, spanning research & discovery, bioproduction & preclinical testing ▪ Diversified offerings that span the gamut of preclinical workflows & applications ▪ Top - tier market positions across the majority of product lines Drug Discovery Life Cycle & Where We Fit In Preclinical Systems Products Cellular & Molecular Technology (CMT) Products Amino Acid Analyzers Broad Portfolio Serves as One Stop Shop for Customers 14

RECURRING & HIGH - MARGIN Integrated hardware, consumables, & advanced analysis software ▪ Creates high switching costs & expanding recurring revenue streams MCS Software Platform FIRST & DIFFERENTIATED Industry’s first platform for long - term functional recording inside living organoids ▪ Enables continuous neuro & cardiac data over weeks to months MeshMEA TM Organoids & MeshMEA : Powering Shift to Human - Relevant Discovery FASTER & MORE PREDICTIVE Earlier safety & efficacy insights versus traditional animal models ▪ Improves compound selection while reducing development time & cost MEA2100 Mini System Incub8 TM System 15

HIGH - GROWTH PLATFORMS: FROM INVESTMENT TO IMPACT CMT - ORGANOIDS CMT Bio - Production In - Vitro Organoid Apps STRENGTHEN THE BASE: MARKET LEADERSHIP & PROFITABLE GROWTH PRECLINICAL ▪ Ponemah TM Enterprise Data Acquisition/Analysis GLP ▪ Introduced 2 nd release of SoHo shared housing implantable telemetry system to extend leadership in wireless telemetry ▪ Introduced VivaMARS TM high - volume GLP behavioral system ▪ Well established cellular/molecular/inhalation - respiration technologies for research/discovery ▪ Recurring revenue streams from consumables, software & services NPI Pipeline Provides High Growth Opportunities ▪ BTX® electroporation / electrofusion system ▪ Supports latest applications in cell & gene editing, cell & gene therapy (CGT) ▪ Introduced BTX & Amino Acid Analysis for bioproduction ▪ Introduced breakthrough MeshMEA TM organoid platform ▪ Leverages leadership position in advanced electrophysiology with Incub 8 TM platform ▪ Adapts leading MEA technology to emerging organoid applications in neuro & cardiac safety toxicology 16

▪ 54% recurring revenue in 2025 ▪ Clear path to 60% recurring revenue ▪ Focusing NPI on resources & investments on higher - margin consumables service & software 46% 54% ▪ Improvement driven by cost reductions to date ▪ Maintaining cost discipline & operational efficiency going forward ▪ Differentiated & innovative high - margin platforms such as SoHo telemetry, & proprietary MeshMEA & Incub8 platforms 46% non - recurring equipment revenue 54% recurring consumables, software & services revenue Note: represents full year 2025 revenue mix ▪ Cash generation driven by operational improvements ▪ Manufacturing consolidation expected to unlock additional efficiencies ▪ Additional cash will provide opportunity to invest in innovation Recurring Revenue High Gross Margin Positive Cash Flow Recurring Revenue, Strong Margins & Cash Generation 17

$ Million except per share data * Non - GAAP measure, see Slide 28 - 30 for reconciliation to GAAP financial measures 1Q26 Financial Metrics (GAAP except where noted) GAAP 18 ADJUSTED $12.2 $12.2 $0.8 $0.8 ▪ Cash flow from operations decreased primarily due to higher inventory as well as one - time costs related to the reverse split and S3 filing

REVENUE 2Q26 Revenue between $20.5M - $22.5M FY26 Revenue growth between 2% - 4% ADJ. GROSS MARGIN 2Q26 GM between 57% - 59% FY26 GM between 58% - 60% ADJ. EBITDA 2Q26 Adj. EBITDA between $1M - $2M FY26 Adj. EBITDA growth between 6% - 10% Outlook

Investment Highlights: Strong Foundation Poised for Growth Market Leadership with Structural Tailwinds #1 preclinical telemetry franchise for 35+ years, & early organoid leadership Blue - Chip Customer Base Selling to diverse, blue - chip customer base on a global scale Recurring Revenue, High Margins & Positive Cash Flow Software, consumables, installed base drive visibility & margin expansion on products with high barrier to entry, generating increased cash for the Company Differentiated New Product Innovation (NPI) Pipeline MeshMEA , SoHo , Incub8 extend leadership into high - growth adjacencies New Management & BoD Refocused management team with deep experience supported by technically deep employee base & refreshed board of directors Strengthened Balance Sheet & Streamlined Operations 20 Refinancing & manufacturing consolidation unlock operating leverage

Appendix 21

Leading Reputation, with Multiple Competitive Advantages A differentiated platform with durable market leadership Breadth Across the Translational Workflow ▪ Only provider spanning in vivo telemetry & in vitro organoid platforms ▪ Enables standardized data & cross - selling across development stages Creates durable market leadership, strong pricing power, & long - term revenue visibility First - Mover & Technology Leadership ▪ Category - defining MeshMEA & decades of electrophysiology expertise ▪ Continuous innovation extending leadership into high - growth markets Sticky Installed Base & Recurring Revenue ▪ Mission - critical software embedded in regulated customer workflows ▪ High switching costs with growing consumables & service revenue Robust Data & Brand Equity ▪ Proprietary platforms validated in CRO & pharma environments ▪ Long - standing relationships & strong scientific reputation 22

Revenue Breakdown 23 % Var 1Q25 1Q26 HBIO Revenue Americas decrease due to NIH funding delays which caused lower academic and government sales - 9% $10.7M $9.7M Americas EMEA increase due to strong NPI uptake, with higher sales from distribution partners and to pharma customers 7% $6.0M $6.5M EMEA APAC decrease due to lower sales from distribution partners; China increase due to higher sales to CROs - 9% +3% $5.1M $2.7M $4.6M $2.8M APAC China - 5% $21.8M $20.8M HBIO Total

Cellular & Molecular Technology (CMT) Innovation & High - Growth Applications x Positioned at the center of NAM adoption & human - relevant research models x Leading electrophysiology platforms supporting discovery, translational, & organoid research x First - of - its - kind MeshMEA system enabling long - term organoid data acquisition x Expanding into gene editing, bioproduction, & next - generation in vitro workflows Preclinical Systems Market Leadership & Cash Generation x Global leader in implantable & external telemetry for safety pharmacology & toxicology x Mission - critical data acquisition & regulatory - ready software platforms x High recurring revenue from software, consumables, & long - term customer relationships x Cash flow foundation funding innovation & expansion across the portfolio ~$40M FY25A Rev. ~$47M FY25A Rev. Diversified Platform Powering the Full Translational Workflow Two complementary engines covering critical stages of drug discovery through preclinical development while driving cash flow today & growth tomorrow 46% 24 54%

Bio - Production Regulatory Report LARGE / NHP MODEL CLINICAL SAFETY/TOX Preclinical Safety & Toxicology Low Yield LARGE POPULATION SMALL MODEL SAFETY/TOXICOLOGY ORGANOIDS Research & Discovery CELLULAR TESTINGS COMPOUND CREATION Inhalation / Respiratory VivaMARS TM Neuro - Behavioral System High - capacity behavior Assessment New: SoHo TM Implantable Telemetry System Measurement of biopotentials in small lab animals Maximize data output while minimizing costs Captures physiological data from freely moving animals within social groups Implantable / External Telemetry Collects basic respiratory endpoints & performs lung function analysis Includes small & large animal applications Ponemah Data Management Software designed for optimal data acquisition & analysis Denotes New Products Pre - Clinical Systems Products 25

Research & Discovery Preclinical Safety & Toxicology CELLULAR TESTINGS COMPOUND CREATION CLINICAL SMALL MODEL SAFETY/TOXICOLOGY LARGE / NHP MODEL SAFETY/TOX Bio - Production Regulatory Report Low Yield ORGANOIDS LARGE POPULATION BTX® Electroporation / Electrofusion Electroporation technology bridges from therapy to production Cellular Platforms (MEA / Patchclamp) Precision Electrophysiology First: MeshMEA Organoid Platform In - Vitro Electrophysiology Analysis Reduce test time/cost, increase yield Neuro & cardiac longitudinal studies Perfect for New Approach Methodologies (NAMs) Spectrophotometers Composition analysis to support molecular testing High Precision Syringe Pumps Injection & perfusion applications Amino Acid Analyzers Protein analysis of buffers & solutions Denotes New Products Cellular & Molecular Technology (CMT) Products 26

Non - GAAP Reconciliation Tables 27

(1) Other operating expenses for the three months ended March 31, 2026 includes $235 thousand of restructuring - related charges compared to $93 thousand of restructuring - related charges and $171 thousand of employee retention tax credit fees for the three months ended March 31, 2025. (2) Interest expense for the three months ended March 31, 2026 was $1.7 million, compared to $0.9 million for the three months ended March 31, 2025. Other expense, net was $405 thousand for the three months ended March 31, 2026, compared to $193 thousand for the three months ended March 31, 2025. (3) Adjusted income taxes includes the tax effect of adjusting for the reconciling items using the tax rates in the jurisdictions in which the reconciling items arise. Non - GAAP Reconciliation Table – Adjusted EBITDA 29

2025 March 31, 2026 $ 35,958 $ 36,211 Debt, including unamortized deferred financing costs 392 3,789 Unamortized deferred financing costs (5,546) (7,098) Cash and cash equivalents $ 30,804 $ 32,902 Net debt Non - GAAP Reconciliation Tables – Adjusted EPS & Net Debt 30 Three Months Ended 3/31/2025 Three Months Ended 3/31/2026 (11.42) $ (0.77) $ Diluted loss per share (GAAP) * (1.25) $ (0.33) $ Diluted adjusted loss per share * 4,410 4,473 Weighted average common shares: Diluted GAAP * 4,410 4,473 Diluted Adjusted * * Retroactively presented to reflect 1 - for - 10 reverse stock split effective on March 13, 2026.

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XML — IDEA: XBRL DOCUMENT

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v3.26.1

Cover

May 12, 2026

Cover [Abstract]

Document Type

8-K

Amendment Flag

false

Document Period End Date

May 12, 2026

Entity File Number

001-33957

Entity Registrant Name

HARVARD BIOSCIENCE, INC.

Entity Central Index Key

0001123494

Entity Tax Identification Number

04-3306140

Entity Incorporation, State or Country Code

Entity Address, Address Line One

84 October Hill Road

Entity Address, City or Town

Holliston

Entity Address, State or Province

Entity Address, Postal Zip Code

01746

City Area Code

(508)

Local Phone Number

893-8999

Written Communications

false

Soliciting Material

false

Pre-commencement Tender Offer

false

Pre-commencement Issuer Tender Offer

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Title of 12(b) Security

Common Stock, $0.01 par value

Trading Symbol

HBIO

Security Exchange Name

NASDAQ

Entity Emerging Growth Company

false

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Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.

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Area code of city

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Cover page.

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For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.

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The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

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No definition available.

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Address Line 1 such as Attn, Building Name, Street Name

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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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- Definition

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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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

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Indicate if registrant meets the emerging growth company criteria.

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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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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Section 14d

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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Subsection 12

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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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