# EDGAR Filing Document

**Accession Number:** 0000927003
**File Stem:** 0001104659-26-072131
**Filing Date:** 2026-6
**Character Count:** 157042
**Document Hash:** 731ed379b0fb0f2a4e01dba5df12ff79
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-26-072131.hdr.sgml**: 20260622

**ACCESSION NUMBER**: 0001104659-26-072131

**CONFORMED SUBMISSION TYPE**: S-3ASR

**PUBLIC DOCUMENT COUNT**: 15

**FILED AS OF DATE**: 20260610

**DATE AS OF CHANGE**: 20260610

**EFFECTIVENESS DATE**: 20260610

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** ADVANCED ENERGY INDUSTRIES INC
- **CENTRAL INDEX KEY:** 0000927003
- **STANDARD INDUSTRIAL CLASSIFICATION:** ELECTRONIC COMPONENTS, NEC [3679]
- **ORGANIZATION NAME:** 04 Manufacturing
- **EIN:** 840846841
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** S-3ASR
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-296659
- **FILM NUMBER:** 261078294

**BUSINESS ADDRESS:**
- **STREET 1:** ATTN:  PAUL OLDHAM
- **STREET 2:** 1595 WYNKOOP ST, SUITE 800
- **CITY:** DENVER
- **STATE:** CO
- **ZIP:** 80202
- **BUSINESS PHONE:** 9704076626

**MAIL ADDRESS:**
- **STREET 1:** ATTN:  PAUL OLDHAM
- **STREET 2:** 1595 WYNKOOP ST, SUITE 800
- **CITY:** DENVER
- **STATE:** CO
- **ZIP:** 80202

**As filed with the Securities and Exchange Commission on June 10, 2026**

**Registration No. 333-**

**UNITED STATES<br> SECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

**FORM S-3**

**REGISTRATION STATEMENT<br> UNDER<br> THE SECURITIES ACT OF 1933**

**ADVANCED ENERGY INDUSTRIES, INC.**

(Exact name of registrant as specified in its charter)

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| | |
|:---|:---|
| **Delaware**<br> (State or other jurisdiction of incorporation or organization) | **84-0846841**<br> (I.R.S. Employer<br> Identification No.) |

---

**1595 Wynkoop Street, Suite 800<br> Denver, Colorado 80202<br> 970-407-6626**<br> (Address, including zip code, and telephone number,<br> including area code, of registrant's principal executive offices)

**Elizabeth K. Vonne<br> Executive Vice President, General Counsel & Corporate Secretary<br> 1595 Wynkoop Street, Suite 800<br> Denver, Colorado 80202<br> 970-407-6626**<br> (Name, address, including zip code, and telephone number,<br> including area code, of agent for service)

**with a copy to**:

**Garrett F. Bishop<br> Foley & Lardner LLP<br> 777 East Wisconsin Avenue<br> Milwaukee, Wisconsin 53202-5306<br> (414) 319-7024**

**Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this registration statement.**

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. ¨

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. x

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ¨

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. x

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company" and "emerging growth company" in Rule 12b-2 of the Exchange Act.

Large accelerated filer ⌧ Accelerated filer ◻ Non-accelerated filer ◻ Smaller reporting company ◻ 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 7(a)(2)(B) of the Securities Act. ¨

**Prospectus**

**Advanced Energy Industries, Inc.**

**Debt Securities<br> Common Stock<br> Preferred Stock<br> Warrants<br> Purchase Contracts<br> Purchase Units**

**Units**

We may offer and sell from time to time these securities in one or more classes or series and in amounts, at prices and on terms that we will determine at the times of the offerings. In addition, selling stockholders to be named in a prospectus supplement may offer and sell from time to time shares of our common stock in such amounts as set forth in a prospectus supplement. Unless otherwise set forth in a prospectus supplement, we will not receive any proceeds from the sale of shares of our common stock by any selling stockholders.

We will provide specific terms of the securities, including the offering prices, in one or more supplements to this prospectus. The supplements may also add, update or change information contained in this prospectus. You should read this prospectus and the prospectus supplement relating to the specific issue of securities carefully before you invest.

We may offer the securities independently or together in any combination for sale directly to purchasers or through underwriters, dealers or agents to be designated at a future date. The supplements to this prospectus will provide the specific terms of the plan of distribution.

Our common stock is traded on the Nasdaq Global Select Market under the symbol "AEIS." Our executive offices are located at 1595 Wynkoop Street, Suite 800, Denver, Colorado 80202, and our telephone number is 970-407-6626.

**Investment in our securities involves risks. You should consider the risks described under "Risk Factors" on page [2](#a_003) of this prospectus, as well as the other information contained or incorporated by reference in this prospectus or the applicable prospectus supplement, before making an investment in the securities which may be offered hereby.**

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is June 10, 2026.

**TABLE OF CONTENTS**

---

| | |
|:---|:---|
|  | **<u>Page</u>** |
| [About This Prospectus](#a_001) | [1](#a_001) |
| [Special Note Regarding Forward-Looking Statements](#a_002) | [1](#a_002) |
| [Risk Factors](#a_003) | [2](#a_003) |
| [Advanced Energy Industries, Inc.](#a_004) | [3](#a_004) |
| [Use of Proceeds](#a_005) | [3](#a_005) |
| [Description of Capital Stock](#a_006) | [3](#a_006) |
| [Description of the Debt Securities](#a_007) | [4](#a_007) |
| [Description of Warrants](#a_008) | [12](#a_008) |
| [Description of the Purchase Contracts and Purchase Units](#a_009) | [13](#a_009) |
| [Description of Units](#a_010) | [14](#a_010) |
| [Where You Can Find More Information](#a_011) | [14](#a_011) |
| [Selling Stockholders](#a_012) | [15](#a_012) |
| [Plan of Distribution](#a_013) | [15](#a_013) |
| [Legal Matters](#a_014) | [17](#a_014) |
| [Experts](#a_015) | [17](#a_015) |

---

**About This Prospectus**

All references to "Advanced Energy," the "company," "we," "us" and "our" in this prospectus mean, unless we otherwise indicate or the context indicates otherwise, Advanced Energy Industries, Inc. together with its consolidated subsidiaries. All references in this prospectus to our consolidated financial statements include, unless the context indicates otherwise, the related notes.

This prospectus is part of a registration statement that we filed with the United States Securities and Exchange Commission (the "SEC") utilizing a "shelf" registration process. Under this shelf process, we may, from time to time, sell the securities or combinations of the securities described in this prospectus, and one or more of our stockholders may sell our common stock, in one or more offerings. This prospectus provides you with a general description of those securities. Each time we offer securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may also add, update or change information contained in this prospectus. If there is any inconsistency between the information in this prospectus and any prospectus supplement, you should rely on the information in the prospectus supplement. You should read both this prospectus and any prospectus supplement together with additional information described under the heading "Where You Can Find More Information."

You should rely only on the information contained or incorporated by reference in this prospectus and in any prospectus supplement and/or other offering material. "Incorporated by reference" means that we can disclose important information to you by referring you to another document filed separately with the SEC. We have not authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We are not making offers to sell or solicitations to buy the securities in any jurisdiction in which an offer or solicitation is not authorized or in which the person making that offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make an offer or solicitation. You should not assume that the information in this prospectus or any prospectus supplement, as well as the information we file or previously filed with the SEC that we incorporate by reference in this prospectus or any prospectus supplement, is accurate as of any date other than its respective date. Our business, financial condition, results of operations and prospects may have changed since those dates.

**Special Note Regarding Forward-Looking Statements**

This prospectus, any accompanying prospectus supplement and the documents incorporated by reference herein or therein, includes "forward-looking statements" within the meanings of Section 27A of the Securities Act of 1933, as amended (the "Securities Act"), and Section 21E of the Securities Exchange Act of 1934, as amended (the "Exchange Act"). Statements contained in this prospectus, any accompanying prospectus supplement and the documents incorporated by reference herein or therein, that are not historical information are "forward-looking statements." For example, statements relating to our beliefs, expectations and plans are forward-looking statements, as are statements that certain actions, conditions, events, or circumstances will continue. The inclusion of words such as "anticipate," "expect," "estimate," "can," "may," "might," "continue," "enable," "plan," "intend," "should," "could," "would," "will," "likely," "potential," "believe," and similar expressions and the negative versions thereof indicate forward-looking statements; however, not all forward-looking statements may contain such words or expressions.

These forward-looking statements are based upon information available as of the date hereof, the date of any accompanying prospectus supplement or the date of and management's then-current estimates, forecasts, and assumptions. Although we believe that our expectations reflected herein or therein or suggested by these forward-looking statements are reasonable, we may not achieve the results, performance, plans, or objectives expressed or implied by such forward-looking statements. Forward-looking statements involve risks and uncertainties, which are difficult to predict and many of which are beyond our control.

Risks and uncertainties to which our forward-looking statements are subject include:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· volatility and cyclicality, economic conditions, and business fluctuations in the industries in which we compete;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· risks associated with availability and price of certain semiconductor and other components which may be in limited supply relative
to global demand;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· risks related to global economic and political conditions, such as the impact of tariffs and export regulations, escalating global
conflicts on macroeconomic conditions, including recent developments in the Middle East, economic uncertainty, market volatility, rising
interest rates, inflation, lack of growth in our markets, fluctuations in commodity prices and currency exchange rates, or recession;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· our ability to achieve design wins with new and existing customers;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· our ability to accurately forecast and meet customer demand;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· risks associated with scaling our manufacturing capacity and securing sufficient critical components
to meet customer demand;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· pricing pressure from customers and competitors;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· concentration of our customer base;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· risks associated with potential breach of our information security measures— either external
breach or internal data theft;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· difficulties with the implementation of our enterprise resource planning and other enterprise-wide information technology system applications;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· our loss of or inability to attract and retain key personnel;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· risks associated with our manufacturing footprint optimization and movement of manufacturing locations for certain products;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· disruptions to our manufacturing operations or those of our customers or suppliers;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· our ability to successfully identify, close, integrate and realize anticipated benefits from
our acquisitions or divestitures;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· quality issues, unanticipated costs in fulfilling our warranty obligations or adequacy of our warranty reserves, claims outside of
warranty, or product liability claims;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· our ability to enforce, protect and maintain our proprietary technology and intellectual property rights and avoid claims alleging
infringement of the intellectual property rights of others;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· legal matters, claims, investigations, and proceedings;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· changes to tax laws and regulations or our tax rates;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· changes to and maintaining compliance with U.S. federal, state, local and foreign regulations, including with respect to trade compliance,
privacy and data protection, supply chain, and environmental, health and safety regulation;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· effect of our debt obligations and restrictive covenants on our ability to operate our business;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· risks related to our unfunded pension obligations;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· our estimates of the fair value of intangible assets;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· the potential impact of dilution and counterparty default risk related to our convertible debt, hedge, and warrant transactions;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· risks relating to ownership of our common stock; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· the risks and uncertainties described in Part I, Item 1A in the 2025 Form 10-K.

Our actual results could differ materially and adversely from those expressed in any forward-looking statements, and readers are cautioned not to place undue reliance on forward-looking statements. We assume no obligation to update any forward-looking statement or provide the reasons why our actual results might differ.

**Risk Factors**

Investing in our securities involves significant risks. Before making an investment decision, you should carefully consider the risks and other information we include or incorporate by reference in this prospectus and any prospectus supplement. In particular, you should consider the risk factors under the heading "Risk Factors" included in our most recent Annual Report on Form 10-K, as may be revised or supplemented by our subsequent Quarterly Reports on Form 10-Q or Current Reports on Form 8-K, each of which are on file with the SEC and are incorporated herein by reference, and which may be amended, supplemented or superseded from time to time by other reports we file with the SEC in the future. The risks and uncertainties we have described are not the only ones facing our company. Additional risks and uncertainties not currently known to us or that we currently deem immaterial may also affect our business operations and financial condition, which in turn could materially and adversely affect the trading price or value of our securities. As a result, you could lose all or part of your investment. Additional risk factors may be included in a prospectus supplement relating to a particular offering of securities.

**Advanced Energy Industries, Inc.**

Advanced Energy provides highly engineered, critical, precision power conversion, measurement, and control solutions to our global customers. We design, manufacture, sell and service precision power products that transform, refine, and modify the raw electrical power coming from either the utility or the building facility and convert it into various types of highly controllable, usable power that is predictable, repeatable, and customizable to meet the necessary requirements for powering a wide range of complex equipment. Our products enable customers to reduce or optimize their energy consumption through increased power conversion efficiency, power density, power coupling, and process control across a wide range of applications. We are organized on a global, functional basis and operate as a single segment of power electronics conversion products. Within this segment, our products are sold in the semiconductor equipment, data center computing, industrial and medical, and telecom and networking markets.

Our precision power products and solutions are designed to enable process technologies, improve productivity, lower the cost of ownership, and/or provide critical power capabilities for our customers. These products are designed to meet our customers' demanding requirements in efficiency, flexibility, performance, and reliability. We also provide repair and maintenance services for our products. Our plasma power products enable innovation in complex semiconductor and thin film plasma processes such as dry etch and deposition. Our broad portfolio of high and low voltage power products is used in a wide range of applications, such as semiconductor equipment, data center computing, industrial production, medical and life science equipment, aerospace and defense, networking, and telecommunications. We also supply related sensing, controls, and instrumentation products primarily for advanced measurement and calibration of power and temperature for multiple industrial markets. Our network of global service support centers provides repair services, calibration, conversions, upgrades, refurbishments, and used equipment to companies that use our products.

We incorporated in Colorado in 1981 and reincorporated in Delaware in 1995. Our executive offices are located at 1595 Wynkoop Street, Suite 800, Denver, Colorado 80202, and our telephone number is 970-407-6626.

**Use of Proceeds**

Unless otherwise described in the applicable prospectus supplement, we intend to use the net proceeds from the sale of the securities to which this prospectus relates for general corporate purposes. General corporate purposes may include repayment of indebtedness, acquisitions or strategic investments in businesses or technologies, additions to working capital and/or capital expenditures. Pending such use, we may temporarily invest the net proceeds in short-term investments.

We will not receive any proceeds from the sale of shares of common stock by selling stockholders.

**Description of Capital Stock**

We are authorized to issue 140,000,000 shares of our common stock, $0.001 par value per share, and 1,000,000 shares of preferred stock, $0.001 par value per share. The following description of our common stock is a summary and does not purport to be complete. The description is subject to and qualified in its entirety by reference to our Amended and Restated Certificate of Incorporation, as amended (our "Certificate of Incorporation"), our Third Amended and Restated By-Laws (our "By-Laws") and applicable Delaware law.

**Common Stock**

As of April 29, 2026, we had 38,030,657 shares of common stock issued and outstanding.

The holders of our common stock are entitled to one vote for each share held of record on all matters submitted to a vote of stockholders. Approval of a matter submitted to the stockholders generally requires the affirmative vote of a majority of the shares being voted on that matter. The General Corporation Law of the State of Delaware imposes a greater approval requirement on certain matters that may be submitted to stockholders, such as business combinations or the sale of all or substantially all of our assets. Amendments to our Certificate of Incorporation relating to the personal liability of our directors or relating to the requirements applicable to amending our Certificate of Incorporation require the approval of the holders of at least 66 2/3% of the then outstanding voting stock. Our By-Laws may be amended only with the approval of a majority of our board of directors or the holders of at least 66 2/3% of the then outstanding voting stock.

Subject to preferences that may be applicable to any outstanding shares of preferred stock that may be issued, the holders of our common stock are entitled to receive ratably any dividends that may be declared from time to time by the board of directors out of funds legally available for the payment of dividends. The holders of our common stock are entitled to share ratably in all assets remaining after payment of liabilities and liquidation preferences of any outstanding shares of preferred stock in the event of our liquidation, dissolution or winding up. Holders of our common stock have no preemptive rights or rights to convert their common stock into any other securities. There are no redemption or sinking fund provisions applicable to our common stock. All outstanding shares of our common stock are fully paid and non-assessable.

The transfer agent and registrar for our common stock is Equiniti Trust Company, LLC.

**Preferred Stock**

Our board of directors has the authority, without further action by the stockholders, to issue up to 1,000,000 shares of preferred stock, in one or more series, and to fix the rights, privileges and preferences of such shares of preferred stock. The rights, privileges and preferences of any series of preferred stock likely will be greater than the rights, privileges and preferences of the common stock. The issuance of preferred stock could adversely affect the voting power of the common stock and reduce the likelihood that the common stockholders will receive dividends or payments upon liquidation of our company. An issuance of preferred stock also may have the effect of delaying, deterring or preventing a change in control of the company.

**Certain Statutory Provisions**

*Anti-takeover Effects of Section 203 of the Delaware General Corporation Law .* We are subject to Section 203 of the Delaware General Corporation Law, an anti-takeover law. In general, Section 203 prohibits a Delaware corporation from engaging in any business combination with an "interested stockholder" for a period of three years following the date that the stockholder became an interested stockholder, subject to specified exceptions.

Section 203 defines an "interested stockholder" as a person who, together with affiliates and associates, owns, or, in some cases, within three years prior, did own, 15% or more of the corporation's voting stock. Section 203 does not prohibit a business combination with an interested stockholder, if:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· prior to that date, the board of directors of the corporation approved either the business combination or the transaction that resulted in the stockholder becoming an interested stockholder;

· upon consummation of the transaction that resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of the voting stock of the corporation outstanding at the time the transaction commenced, excluding for purposes of determining the number of shares of voting stock outstanding (but not the voting stock owned by the interested stockholder) those shares owned by persons who are directors and also officers and by excluding employee stock plans in which employee participants do not have the right to determine confidentially whether shares held subject to the plan will be tendered in a tender or exchange offer; or

· on or subsequent to that date, the business combination is approved by the board of directors of the corporation and authorized at an annual or special meeting of stockholders, and not by written consent, by the affirmative vote of at least 66 2/3% of the outstanding voting stock that is not owned by the interested stockholder.

Section 203 defines a "business combination" to include the following:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· any merger or consolidation involving the corporation and the interested stockholder;

· any sale, transfer, pledge or other disposition of 10% or more of the assets of the corporation involving the interested stockholder;

· subject to certain exceptions, any transaction that results in the issuance or transfer by the corporation of any stock of the corporation to the interested stockholder;

· any transaction involving the corporation that has the effect of increasing the proportionate share of the stock of any class or series of the corporation beneficially owned by the interested stockholder; or

· the receipt by the interested stockholder of the benefit of any loans, advances, guarantees, pledges or other financial benefits provided by or through the corporation.

**Description of the Debt Securities**

The following description of the debt securities sets forth the general terms and provisions of the debt securities to which any prospectus supplement and/or other offering material may relate. We will describe the specific terms of the debt securities and the extent, if any, to which the general provisions summarized below apply to any series of debt securities in the prospectus supplement and/or other offering material that we authorized to be delivered. As used in this section, the terms "we," "us," "our," "Advanced Energy" and the "company" refer to Advanced Energy Industries, Inc., a Delaware corporation, and not any of its subsidiaries, unless the context requires.

The debt securities will represent unsecured and unsubordinated general obligations, unless otherwise provided in the prospectus supplement. Senior debt securities will be issued under an indenture between us and a trustee named in the prospectus supplement, a form of which is filed as an exhibit to the registration statement of which this prospectus is a part. The indenture relating to the senior debt securities, as amended or otherwise supplemented by any supplemental indentures, is referred to in this prospectus as the indenture.

The following summaries of the material provisions of the indenture and the debt securities do not purport to be complete and are subject to, and are qualified in their entirety by reference to, all of the provisions of the indenture and the debt securities, including the definitions therein. Wherever particular articles, sections or defined terms of an indenture are referred to, it is intended that those articles, sections or defined terms will be incorporated herein by reference, and the statement in connection with which reference is made is qualified in its entirety by the article, section or defined term in the indenture.

**General**

The indenture does not limit the amount of debt securities that may be issued under the indenture, and the indenture does not limit the amount of other unsecured debt or securities that we may issue. The debt securities may be issued in one or more series with the same or various maturities and may be sold at par, a premium or an original issue discount. Some of the debt securities may be issued under the indenture as original issue discount securities to be sold at a substantial discount below their principal amount. Federal income tax and other considerations applicable to any original issue discount securities will be described in the related prospectus supplement and/or other offering material. We have the right to "reopen" a previous issue of a series of debt by issuing additional debt securities of such series.

Our right to participate as a stockholder in any distribution of assets of any subsidiary upon its liquidation or reorganization or otherwise and the ability of a holder of debt securities to benefit as our creditor from any distribution are subject to prior claims of creditors of the subsidiary. The debt securities will also effectively rank junior in right of payment to any of our secured debt.

The applicable prospectus supplement and/or other offering material relating to the particular series of debt securities offered thereby will describe the following terms of the offered debt securities:

&nbsp;&nbsp;&nbsp;&nbsp;· the title of the offered debt securities;

&nbsp;&nbsp;&nbsp;&nbsp;· any limit upon the aggregate principal amount of the offered debt securities;

&nbsp;&nbsp;&nbsp;&nbsp;· the date or dates (or the manner of calculating the date or dates) on which the principal of the offered debt securities is payable;

&nbsp;&nbsp;&nbsp;&nbsp;· the rate or rates (or the manner of calculating the rate or rates) at which the offered debt securities shall bear interest, if any,
the date or dates from which such interest shall accrue, the interest payment dates on which such interest shall be payable and the regular
record date for the interest payable on any interest payment date;

&nbsp;&nbsp;&nbsp;&nbsp;· the place or places where the principal of and premium, if any, and interest, if any, on the offered debt securities will be payable;

&nbsp;&nbsp;&nbsp;&nbsp;· the period or periods within which, the price or prices at which, the currency in which, and the terms and conditions upon which the
offered debt securities may be redeemed, in whole or in part, at our option;

&nbsp;&nbsp;&nbsp;&nbsp;· our obligation, if any, to redeem or purchase the offered debt securities pursuant to any sinking fund or analogous provisions or
at the option of a holder thereof and the period or periods within which, the price or prices in the currency at which, the currency in
which, and the terms and conditions upon which the offered debt securities shall be redeemed or purchased, in whole or in part, pursuant
to such obligation;

&nbsp;&nbsp;&nbsp;&nbsp;· the denominations in which the offered debt securities shall be issuable if other than denominations of $1,000 and any integral multiple
thereof;

&nbsp;&nbsp;&nbsp;&nbsp;· if other than the currency of the United States of America, the currencies in which payments of interest or principal of (and premium,
if any, with respect to) the offered debt securities are to be made;

&nbsp;&nbsp;&nbsp;&nbsp;· if the interest on or principal of (or premium, if any, with respect to) the offered debt securities are to be payable, at our election
or at the election of a holder thereof or otherwise, in a currency other than that in which such debt securities are payable, the period
or periods within which, and the other terms and conditions upon which, such election may be made, and the time and manner of determining
the exchange rate between the currency in such debt securities are denominated or stated to be payable and the currency in which such
debt securities or any of them are to be so payable;

&nbsp;&nbsp;&nbsp;&nbsp;· whether the amount of payments of interest on or principal of (or premium, if any, with respect to) the offered debt securities of
such series may be determined with reference to an index, formula or other method (which index, formula or method or method may be based,
without limitation, on one or more currencies, commodities, equity indices or other indices), and, if so, the terms and conditions upon
which and the manner in which such amounts shall be determined and paid or payable;

&nbsp;&nbsp;&nbsp;&nbsp;· the extent to which any offered debt securities will be issuable in permanent global form, the manner in which any payments on a permanent
global debt security will be made, and the appointment of any depository relating thereto;

&nbsp;&nbsp;&nbsp;&nbsp;· whether such debt securities will be subject to discharge or defeasance described in this prospectus with respect to the offered debt
securities;

&nbsp;&nbsp;&nbsp;&nbsp;· any deletions from, modifications of or additions to the events of default or covenants with respect to the offered debt securities
of such series, whether or not such events of default or covenants are consistent with the events of default or covenants set forth herein;

&nbsp;&nbsp;&nbsp;&nbsp;· the terms of any repurchase or remarketing rights;

&nbsp;&nbsp;&nbsp;&nbsp;· if any of the offered debt securities are to be issuable upon the exercise of warrants, and, if so, the time, manner and place for
such debt securities to be authenticated and delivered;

&nbsp;&nbsp;&nbsp;&nbsp;· if applicable, the provisions relating to conversion or exchange of any debt securities of the series and the terms and conditions
upon which such debt securities will be so convertible or exchangeable, including the conversion or exchange price, as applicable, or
how it will be calculated and may be adjusted, any mandatory or optional (at the our option or the holder's option) conversion or
exchange features, the applicable conversion or exchange period and the manner of settlement for any conversion or exchange, which may,
without limitation, include the payment of cash as well as the delivery of securities; and

&nbsp;&nbsp;&nbsp;&nbsp;· any additional, eliminated, changed, or other terms of the series (which terms shall not be inconsistent with the provisions of the
related indenture).

*Payments*

Unless otherwise indicated in any prospectus supplement and/or other offering material, principal of and premium, if any, and interest, if any, on the offered debt securities will be payable, and transfers of the offered debt securities will be registrable, at the corporate trust office of the trustee. Alternatively, at our option, payment of interest may be made by check mailed to the address of the person entitled thereto as it appears in the debt security register or by wire transfer to an account in such currency designated by such person.

*Denominations, Registration and Transfer* 

Unless otherwise indicated in any prospectus supplement and/or other offering material, the offered debt securities will be issued only in fully registered form without coupons in denominations of $1,000 or any integral multiple of $1,000, or the equivalent in foreign currency. Except as provided in the indenture, pursuant to a Board resolution, an officer's certificate or a supplemental indenture, no service charge will be made for any registration of transfer or exchange of offered debt securities or conversion or exchange of less than the entire principal amount of a debt security, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with any transfer or exchange.

If the purchase price of any of the offered debt securities is denominated in a foreign currency or currencies or if the principal of, premium, if any, or interest, if any, on any series of offered debt securities is payable in a foreign currency or currencies, the restrictions, elections, tax consequences, specific terms and other information with respect to the issue of offered debt securities and the foreign currency or currencies will be described in the related prospectus supplement and/or other offering material.

We will not be required to issue, register the transfer of, or exchange debt securities of any series during the period from 15 days prior to the mailing of a notice of redemption of debt securities of that series to the date the notice is mailed. We will also not be required to register the transfer of or exchange any debt security so selected for redemption, except the unredeemed portion of any debt security being redeemed in part.

*Conversion and Exchange* 

The terms, if any, on which debt securities of any series are convertible into or exchangeable for common stock or preferred stock, property or cash, or a combination of any of the foregoing, will be set forth in the related prospectus supplement and/or other offering material. Terms may include provisions for conversion or exchange that is either mandatory, at the option of the holder, or at our option. The number of shares of common stock or preferred stock to be received by the holders of the debt securities will be calculated in the manner, according to the factors and at the time as described in the related prospectus supplement and/or other offering material.

**Merger** 

The indenture provides that we may, without the consent of the holders of debt securities, consolidate with, or sell, lease or convey all or substantially all of our assets to, or merge into any other corporation, provided that:

&nbsp;&nbsp;&nbsp;&nbsp;· immediately after giving effect to the transaction, no default under the indenture has occurred and is continuing;

&nbsp;&nbsp;&nbsp;&nbsp;· the successor corporation is a corporation organized and existing under the laws of the United States or a state thereof; and

&nbsp;&nbsp;&nbsp;&nbsp;· the successor corporation expressly assumes the due and punctual payment of the principal of and premium, if any, and interest on
all debt securities, according to their tenor, and the due and punctual performance and observance of all the covenants and conditions
of the indenture to be performed by us.

In addition, we must provide to the trustee an opinion of legal counsel that any such transaction and any assumption by a successor corporation complies with the applicable provisions of the indenture and that we have complied with all conditions precedent provided in the indenture relating to such transaction.

Other than the covenants described above, or as set forth in any accompanying prospectus supplement and/or other offering material, the indenture does not contain any covenants or other provisions designed to afford holders of the debt securities protection in the event of a takeover, recapitalization or a highly leveraged transaction involving us.

**Modification of the Indenture** 

With the consent of the holders of more than 50% in aggregate principal amount of any series of debt securities then outstanding under the indenture, waivers, modifications and alterations of the terms of the indenture may be made which affect the rights of the holders of the series of debt securities. However, no modification or alteration may, without the consent of all holders of any series of debt securities then outstanding affected thereby:

&nbsp;&nbsp;&nbsp;&nbsp;· extend the fixed maturity of any debt security of that series;

&nbsp;&nbsp;&nbsp;&nbsp;· reduce the rate or extend the time of payment of interest thereon;

&nbsp;&nbsp;&nbsp;&nbsp;· reduce the principal amount thereof or any premium thereon;

&nbsp;&nbsp;&nbsp;&nbsp;· make the principal thereof or interest or premium thereon payable in any coin or currency other than that provided in the debt securities;
or

&nbsp;&nbsp;&nbsp;&nbsp;· reduce the percentage of debt securities of that series, the holders of which are required to consent to:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· any supplemental indenture;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· rescind and annul a declaration that the debt securities of that series are due and payable as a result of the occurrence of an event
of default;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· waive any past event of default under the indenture and its consequences; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;· waive compliance with other specified provisions of the indenture.

In addition, as described in the description of "Events of Default" set forth below, holders of more than 50% in aggregate principal amount of the debt securities of any series then outstanding may waive past events of default in specified circumstances and may direct the trustee in enforcement of remedies.

We and the trustee may, without the consent of any holders, modify and supplement the indenture:

&nbsp;&nbsp;&nbsp;&nbsp;· to evidence the succession of another corporation to us under the indenture, or successive successions, and the assumption by the
successor corporation of the covenants, agreements and obligations of us pursuant to the indenture;

&nbsp;&nbsp;&nbsp;&nbsp;· to add to the covenants applicable to us such further covenants, restrictions, conditions or provisions as our Board and the trustee
shall consider to be for the protection of the holders of debt securities of any or all series, and to make the occurrence, or the occurrence
and continuance, of a default in any of such additional covenants, restrictions, conditions or provisions a default or event of default
with respect to such series permitting the enforcement of all or any of the several remedies provided in the indenture; provided, however,
that in respect of any such additional covenant, restriction or condition, such supplemental indenture may provide for a particular period
of grace after default (which period may be shorter or longer than that allowed in the case of other defaults) or may provide for an immediate
enforcement upon such default or may limit the remedies available to the trustee upon such default;

&nbsp;&nbsp;&nbsp;&nbsp;· to cure any ambiguity or to correct or supplement any provision contained in the indenture or in any supplemental indenture which
may be defective or inconsistent with any other provision contained in the indenture or in any supplemental indenture;

&nbsp;&nbsp;&nbsp;&nbsp;· to convey, transfer, assign, mortgage or pledge any property to or with the trustee;

&nbsp;&nbsp;&nbsp;&nbsp;· to make other provisions in regard to matters or questions arising under the indenture as shall not adversely affect the interests
of the holders and to make any change that would provide additional rights or benefits to the holders of any or all series or that does
not adversely affect the legal rights under the indenture of any such holder;

&nbsp;&nbsp;&nbsp;&nbsp;· to evidence and provide for the acceptance of appointment by another corporation as a successor trustee under the indenture with respect
to one or more series of debt securities and to add to or change any of the provisions of the indenture as shall be necessary to provide
for or facilitate the administration of the trusts under the indenture by more than one trustee;

&nbsp;&nbsp;&nbsp;&nbsp;· to modify, amend or supplement the indenture in such a manner as to permit the qualification of any supplemental indenture under the
Trust Indenture Act of 1939 as then in effect, except that nothing contained in the indenture shall permit or authorize the inclusion
in any supplemental indenture of the provisions referred to in Section 316(a)(2) of the Trust Indenture Act of 1939;

&nbsp;&nbsp;&nbsp;&nbsp;· to provide for the issuance under the indenture of debt securities in coupon form (including debt securities registrable as to principal
only) and to provide for exchangeability of such debt securities with debt securities of the same series issued hereunder in fully registered
form and to make all appropriate changes for such purpose;

&nbsp;&nbsp;&nbsp;&nbsp;· to change or eliminate any of the provisions of the indenture, provided, however, that any such change or elimination shall become
effective only when there is no debt security outstanding of any series created prior to the execution of such supplemental indenture
which is entitled to the benefit of such provision; and

&nbsp;&nbsp;&nbsp;&nbsp;· to establish any additional form of debt security and to provide for the issuance of any additional series of debt securities.

**Covenant Defeasance and Satisfaction and Discharge of a Series**

*Covenant Defeasance of any Series* 

If we deposit with the trustee, in trust, at or before maturity or redemption:

&nbsp;&nbsp;&nbsp;&nbsp;· lawful money;

&nbsp;&nbsp;&nbsp;&nbsp;· direct obligations of the government which issued the currency in which the debt securities of a series are denominated, or obligations
of a person controlled or supervised by and acting as an agency or instrumentality of such government and which obligations are guaranteed
by such government (which direct or guaranteed obligations are full faith and credit obligations of such government, are denominated in
the currency in which the debt securities of such are denominated and which are not callable or redeemable at the option of the issuer
thereof) in an amount and with a maturity so that the proceeds therefrom will provide funds; or

&nbsp;&nbsp;&nbsp;&nbsp;· a combination thereof,

in each case in an amount sufficient, after payment of all federal, state and local taxes in respect thereof payable by the trustee, in the opinion of a nationally-recognized firm of independent public accountants expressed in a written certification thereof delivered to the trustee, to pay when due the principal, premium, if any, and interest to maturity or to the redemption date, as the case may be, with respect to any series of debt securities then outstanding, and any mandatory sinking fund payments or similar payments or payment pursuant to any call for redemption applicable to such debt securities of such series on the day on which such payments are due and payable in accordance with the terms of the indenture and such debt securities, then the provisions of the indenture would no longer be effective as to the debt securities to which such deposit relates, including the restrictive covenants described in this prospectus or any prospectus supplement relating to such debt securities, except as to:

&nbsp;&nbsp;&nbsp;&nbsp;· our obligation to duly and punctually pay the principal of and premium, if any, and interest on the series of debt securities if the
debt securities are not paid from the money or securities held by the trustee;

&nbsp;&nbsp;&nbsp;&nbsp;· certain of the events of default described under "Events of Default" below; and

&nbsp;&nbsp;&nbsp;&nbsp;· other specified provisions of the indenture including, among others, those relating to registration, transfer and exchange, lost or
stolen securities, maintenance of place of payment and, to the extent applicable to the series, the redemption and sinking fund provisions
of the indenture.

Defeasance of debt securities of any series is subject to the satisfaction of specified conditions, including, among others, the absence of an event of default at the date of the deposit and the perfection of the holders' security interest in the deposit.

*Satisfaction and Discharge of any Series* 

Upon the deposit of money or securities contemplated above and the satisfaction of specified conditions, the provisions of the indenture (excluding the exceptions discussed above under the heading "Covenant Defeasance of any Series") would no longer be effective as to the related debt securities, we may cease to comply with our obligation to pay duly and punctually the principal of and premium, if any, and interest on a particular series of debt securities, the events of default in the indenture no longer would be effective as to such debt securities and thereafter the holders of the series of debt securities will be entitled only to payment out of the money or securities deposited with the trustee.

The specified conditions include, among others, except in limited circumstances involving a deposit made within one year of maturity or redemption:

&nbsp;&nbsp;&nbsp;&nbsp;· the absence of an event of default at the date of deposit or on the 91st day thereafter;

&nbsp;&nbsp;&nbsp;&nbsp;· our delivery to the trustee of an opinion of nationally-recognized tax counsel, or our receipt or publication of a ruling by the Internal
Revenue Service, to the effect that holders of the debt securities of the series will not recognize income, gain or loss for federal income
tax purposes as a result of the deposit and discharge, and the holders will be subject to federal income tax on the same amounts and in
the same manner and at the same times as would have been the case if the deposit and discharge had not occurred; and

&nbsp;&nbsp;&nbsp;&nbsp;· that we receive an opinion of counsel to the effect that the satisfaction and discharge will not result in the delisting of the debt
securities of that series from any nationally-recognized exchange on which they are listed.

**Repurchases on the Open Market**

The company or any affiliate of the company may at any time or, from time to time, repurchase any debt security in the open market or otherwise. Such debt securities may, at the option of the company or the relevant affiliate of the company, be held, resold or surrendered to the trustee for cancellation.

**Events of Default** 

As to any series of debt securities, an event of default is defined in the indenture as being:

&nbsp;&nbsp;&nbsp;&nbsp;· failure to pay any interest on the debt securities of that series when due, which failure continues for 30 days;

&nbsp;&nbsp;&nbsp;&nbsp;· failure to pay principal or premium, if any, with respect to the debt securities of that series when due;

&nbsp;&nbsp;&nbsp;&nbsp;· failure to pay or satisfy any sinking fund payment or similar obligation with respect to debt securities of that series when due;

&nbsp;&nbsp;&nbsp;&nbsp;· failure to observe or perform any other covenant, warranty or agreement in the indenture or debt securities of that series, other
than a covenant, warranty or agreement, a default in whose performance or whose breach is specifically dealt with in the section of the
indenture governing events of default, if the failure continues for 90 days after we receive written notice by the trustee or the holders
of at least 25% in aggregate principal amount of the debt securities of that series then outstanding;

&nbsp;&nbsp;&nbsp;&nbsp;· specified events of bankruptcy, insolvency, receivership or reorganization; or

&nbsp;&nbsp;&nbsp;&nbsp;· any other event of default provided with respect to debt securities of that series.

*Notice and Declaration of Defaults* 

So long as the debt securities of any series remain outstanding, we will be required to furnish annually to the trustee a certificate of one of our corporate officers stating whether, to such officer's knowledge, we are in default under any of the provisions of the indenture, or else specifying all defaults, and the nature thereof, of which such officer has knowledge. We will also be required to furnish to the trustee copies of specified reports filed by us with the SEC which will be deemed filed with the trustee when we file such reports pursuant to the SEC's Electronic Data Gathering, Analysis and Retrieval (or EDGAR) system.

The indenture provides that the trustee will, within 90 days after the occurrence of a default with respect to any series for which there are debt securities outstanding which is continuing, give to the holders of those debt securities notice of all uncured defaults known to it, including events specified above without grace periods. Except in the case of default in the payment of principal, premium, if any, or interest on any of the debt securities of any series or the payment of any sinking fund installment on the debt securities of any series, the trustee may withhold notice to the holders if the trustee in good faith determines that withholding notice is in the interest of the holders of the debt securities.

If a specified event of bankruptcy, insolvency, receivership, or reorganization occurs and is continuing, then the principal amount of (or, if the debt securities of that series are original issue discount debt securities, such portion of the principal amount as may be specified in their terms as due and payable upon acceleration) and any accrued and unpaid interest on that series will immediately become due and payable without any declaration or other act on the part of the trustee or any holder. If any other event of default occurs and is continuing, the trustee or the holders of not less than 25% in aggregate principal amount of the outstanding debt securities of any series may declare the debt securities of that series immediately due and payable. In some cases, the holders of a majority in principal amount of the debt securities of any series then outstanding may waive any past default and its consequences, except a default in the payment of principal, premium, if any, or interest, including sinking fund payments.

*Actions upon Default* 

Subject to the provisions of the indenture relating to the duties of the trustee in case an event of default with respect to any series of debt securities occurs and is continuing, the indenture provides that the trustee will be under no obligation to exercise any of its rights or powers under the indenture at the request, order or direction of any of the holders of debt securities outstanding of any series unless the holders have offered to the trustee reasonable indemnity. The right of a holder to institute a proceeding with respect to the indenture is subject to conditions precedent including notice and indemnity to the trustee, but the holder has a right to receipt of principal, premium, if any, and interest on their due dates or to institute suit for the enforcement thereof, subject to specified limitations with respect to defaulted interest.

The holders of a majority in principal amount of the debt securities outstanding of the series in default will have the right to direct the time, method and place for conducting any proceeding for any remedy available to the trustee, or exercising any power or trust conferred on the trustee. Any direction by the holders will be in accordance with law and the provisions of the related indenture, provided that the trustee may decline to follow any such direction if the trustee determines on the advice of counsel that the proceeding may not be lawfully taken or would be materially or unjustly prejudicial to holders not joining in the direction. The trustee will be under no obligation to act in accordance with the direction unless the holders offer the trustee reasonable security or indemnity against costs, expenses and liabilities which may be incurred thereby.

**Governing Law** 

The indenture and the debt securities will be governed by, and construed in accordance with, the laws of the State of New York.

**Concerning the Trustee** 

We may from time to time maintain lines of credit, and have other customary banking relationships, with the trustee or its affiliates.

The indenture and provisions of the Trust Indenture Act of 1939 that are incorporated by reference in the indenture contain limitations on the rights of the trustee, should it become one of our creditors, to obtain payment of claims in certain cases or to realize on certain property received by it in respect of any such claim as security or otherwise. The trustee is permitted to engage in other transactions with us or any of our affiliates. However, if it acquires any conflicting interest (as defined under the Trust Indenture Act of 1939), it must eliminate such conflict or resign.

**Book-Entry, Delivery and Settlement**

We will issue the debt securities in whole or in part in the form of one or more global certificates, which we refer to as global securities. We will deposit the global securities with or on behalf of The Depository Trust Company, which we refer to as DTC, and registered in the name of Cede & Co., as nominee of DTC. Beneficial interests in the global securities may be held through the Euroclear System ("Euroclear") and Clearstream Banking, S.A. ("Clearstream") (as indirect participants in DTC).

We have provided the following descriptions of the operations and procedures of DTC, Euroclear and Clearstream solely as a matter of convenience. These operations and procedures are solely within the control of DTC, Euroclear and Clearstream and are subject to change by them from time to time. Neither we, any underwriter nor the trustee take any responsibility for these operations or procedures, and you are urged to contact DTC, Euroclear or Clearstream directly to discuss these matters.

DTC has advised us that:

&nbsp;&nbsp;&nbsp;&nbsp;· DTC is a limited-purpose trust company organized under the New York Banking Law, a "banking organization" within the meaning
of the New York Banking Law, a member of the Federal Reserve System, a "clearing corporation" within the meaning of the New
York Uniform Commercial Code and a "clearing agency" registered under Section 17A of the Exchange Act;

&nbsp;&nbsp;&nbsp;&nbsp;· DTC holds securities that its direct participants deposit with DTC and facilitates the settlement among direct participants of securities
transactions, such as transfers and pledges, in deposited securities through electronic computerized book-entry changes in direct participants'
accounts, thereby eliminating the need for physical movement of securities certificates;

&nbsp;&nbsp;&nbsp;&nbsp;· Direct participants include securities brokers and dealers, trust companies, clearing corporations and other organizations;

&nbsp;&nbsp;&nbsp;&nbsp;· DTC is a wholly-owned subsidiary of The Depository Trust & Clearing Corporation, which is owned by the users of its regulated
subsidiaries;

&nbsp;&nbsp;&nbsp;&nbsp;· Access to the DTC system is also available to indirect participants such as securities brokers and dealers, banks and trust companies
that clear through or maintain a custodial relationship with a direct participant, either directly or indirectly; and

&nbsp;&nbsp;&nbsp;&nbsp;· The rules applicable to DTC and its direct and indirect participants are on file with the SEC.

&nbsp;&nbsp;&nbsp;&nbsp;· We expect that under procedures established by DTC:

&nbsp;&nbsp;&nbsp;&nbsp;· Upon deposit of the global securities with DTC or its custodian, DTC will credit on its internal system the accounts of direct participants
designated by the underwriters with portions of the principal amounts of the global securities; and

&nbsp;&nbsp;&nbsp;&nbsp;· Ownership of the debt securities will be shown on, and the transfer of ownership of the debt securities will be effected only through,
records maintained by DTC or its nominee, with respect to interests of direct participants, and the records of direct and indirect participants,
with respect to interests of persons other than participants.

Investors in the global securities who are participants in DTC's system may hold their interests therein directly through DTC. Investors in the global notes who are not participants may hold their interests therein indirectly through organizations (including Euroclear and Clearstream) which are participants in such system. Euroclear and Clearstream may hold interests in the global securities on behalf of their participants through customers' securities accounts in their respective names on the books of their respective depositories, which are Euroclear Bank S.A./N.V., as operator of Euroclear, and Citibank, N.A., as depository of Clearstream. All interests in a securities, including those held through Euroclear or Clearstream, may be subject to the procedures and requirements of DTC. Those interests held through Euroclear or Clearstream may also be subject to the procedures and requirements of such systems.

The laws of some jurisdictions require that purchasers of securities take physical delivery of those securities in the form of a certificate. For that reason, it may not be possible to transfer interests in a global security to those persons. In addition, because DTC can act only on behalf of its participants, who in turn act on behalf of persons who hold interests through participants, the ability of a person having an interest in a global security to pledge or transfer that interest to persons or entities that do not participate in DTC's system, or otherwise to take actions in respect of that interest, may be affected by the lack of a physical definitive security in respect of that interest.

So long as DTC or its nominee is the registered owner of a global security, DTC or that nominee will be considered the sole owner or holder of the debt securities represented by that global security for all purposes under the indenture and under the debt securities. Except as described below, owners of beneficial interests in a global security will not be entitled to have debt securities represented by that global security registered in their names, will not receive or be entitled to receive the debt securities in the form of a physical certificate and will not be considered the owners or holders of the debt securities under the indenture or under the debt securities, and may not be entitled to give the trustee directions, instructions or approvals. For that reason, each holder owning a beneficial interest in a global security must rely on DTC's procedures and, if that holder is not a direct or indirect participant in DTC, on the procedures of the DTC participant through which that holder owns its interest, to exercise any rights of a holder of debt securities under the indenture or the global security.

Neither we nor the trustee will have any responsibility or liability for any aspect of DTC's records relating to the debt securities or relating to payments made by DTC on account of the debt securities, or any responsibility to maintain, supervise or review any of DTC's records relating to the debt securities.

We will make payments on the debt securities represented by the global securities to DTC or its nominee, as the registered owner of the debt securities. We expect that when DTC or its nominee receives any payment on the debt securities represented by a global security, DTC will credit participants' accounts with payments in amounts proportionate to their beneficial interests in the global security as shown in DTC's records. We also expect that payments by DTC's participants to owners of beneficial interests in the global security held through those participants will be governed by standing instructions and customary practice as is now the case with securities held for the accounts of customers registered in the names of nominees for such customers. DTC's participants will be responsible for those payments.

Payments on the debt securities represented by the global securities will be made in immediately available funds. Transfers between participants in DTC will be made in accordance with DTC's rules and will be settled in immediately available funds.

Transfers between participants in DTC will be effected in accordance with DTC's procedures, and will be settled in same-day funds, and transfers between participants in Euroclear and Clearstream will be effected in accordance with their respective rules and operating procedures.

Cross-market transfers between the participants in DTC, on the one hand, and Euroclear or Clearstream participants, on the other hand, will be effected through DTC in accordance with DTC's rules on behalf of Euroclear or Clearstream, as the case may be, by its depository; however, such cross-market transactions will require delivery of instructions to Euroclear or Clearstream, as the case may be, by the counterparty in such system in accordance with the rules and procedures and within the established deadlines (European time) of such system. Euroclear or Clearstream, as the case may be, will, if the transaction meets its settlement requirements, deliver instructions to its respective depository to take action to effect final settlement on its behalf by delivering or receiving interests in the relevant global security in DTC, and making or receiving payment in accordance with normal procedures for same-day funds settlement applicable to DTC. Euroclear participants and Clearstream participants may not deliver instructions directly to the depositories for Euroclear or Clearstream.

DTC has advised us that it will take any action permitted to be taken by a holder of notes only at the direction of one or more participants to whose account DTC has credited the interests in the global securities and only in respect of such portion of the aggregate principal amount of the notes as to which such participant or participants has or have given such direction. However, if there is an event of default under the notes, DTC reserves the right to exchange the global securities for certificated notes, and to distribute such notes to its participants.

Although DTC, Euroclear and Clearstream have agreed to the foregoing procedures to facilitate transfers of interests in the global securities among participants in DTC, Euroclear and Clearstream, they are under no obligation to perform or to continue to perform such procedures, and may discontinue such procedures at any time. None of the company, the trustee or any of their respective agents will have any responsibility for the performance by DTC, Euroclear or Clearstream or their respective direct or indirect participants of their respective obligations under the rules and procedures governing their operations.

**Exchange of Global Securities for Certificated Securities**

We will issue certificated debt securities to each person that DTC identifies as the beneficial owner of debt securities represented by the global securities upon surrender by DTC of the global securities only if:

&nbsp;&nbsp;&nbsp;&nbsp;· DTC notifies us that it is no longer willing or able to act as a depository for the global securities, and we have not appointed a
successor depository within 90 days of that notice;

&nbsp;&nbsp;&nbsp;&nbsp;· An event of default with respect to the debt securities has occurred and is continuing and the depositary requests the issuance of
the securities in definitive form; or

&nbsp;&nbsp;&nbsp;&nbsp;· We decide not to have the debt securities represented by a global security.

Neither we nor the trustee will be liable for any delay by DTC, its nominee or any direct or indirect participant in identifying the beneficial owners of the related debt securities or for maintaining, supervising or reviewing any records relating to beneficial ownership interests. We and the trustee may conclusively rely on, and will be protected in relying on, instructions from DTC or its nominee, including instructions about the registration and delivery, and the respective principal amounts, of the debt securities to be issued.

**Same Day Settlement and Payment** 

We will make payments in respect of the notes represented by the global securities (including principal, premium, if any, and interest) by wire transfer of immediately available funds to the accounts specified by the global securities holder. We will make all payments of principal, interest and premium, if any, with respect to certificated notes by wire transfer of immediately available funds to the accounts specified by the holders of the certificated notes or, if no such account is specified, by mailing a check to each such holder's registered address. The notes represented by the global securities are expected to be eligible to trade in DTC's Same-Day Funds Settlement System, and any permitted secondary market trading activity in such notes will, therefore, be required by DTC to be settled in immediately available funds. The company expects that secondary trading in any certificated notes will also be settled in immediately available funds.

Because of time zone differences, the securities account of a Euroclear or Clearstream participant purchasing an interest in a global security from a participant in DTC will be credited, and any such crediting will be reported to the relevant Euroclear or Clearstream participant, during the securities settlement processing day (which must be a business day for Euroclear and Clearstream) immediately following the settlement date of DTC. DTC has advised us that cash received in Euroclear or Clearstream as a result of sales of interests in a global securities by or through a Euroclear or Clearstream participant to a participant in DTC will be received with value on the settlement date of DTC but will be available in the relevant Euroclear or Clearstream cash account only as of the business day for Euroclear or Clearstream following DTC's settlement date.

**Description of Warrants**

We may issue warrants for the purchase of debt securities, preferred stock, common stock or other securities. Warrants may be issued independently or together with debt securities, preferred stock or common stock offered by any prospectus supplement and/or other offering material and may be attached to or separate from any such offered securities. Each series of warrants will be issued under a separate warrant agreement to be entered into between us and a bank or trust company, as warrant agent, all as will be set forth in the prospectus supplement and/or other offering material relating to the particular issue of warrants. The warrant agent will act solely as our agent in connection with the warrants and will not assume any obligation or relationship of agency or trust for or with any holders of warrants or beneficial owners of warrants.

The following summary of certain provisions of the warrants does not purport to be complete and is subject to, and is qualified in its entirety by reference to, all provisions of the warrant agreements.

Reference is made to the prospectus supplement and/or other offering material relating to the particular issue of warrants offered pursuant to such prospectus supplement and/or other offering material for the terms of and information relating to such warrants, including, where applicable:

&nbsp;&nbsp;&nbsp;&nbsp;· the designation, aggregate principal amount, currencies, denominations and terms of the series of debt securities purchasable upon
exercise of warrants to purchase debt securities and the price at which such debt securities may be purchased upon such exercise;

&nbsp;&nbsp;&nbsp;&nbsp;· the number of shares of common stock purchasable upon the exercise of warrants to purchase common stock and the price at which such
number of shares of common stock may be purchased upon such exercise;

&nbsp;&nbsp;&nbsp;&nbsp;· the number of shares and series of preferred stock purchasable upon the exercise of warrants to purchase preferred stock and the price
at which such number of shares of such series of preferred stock may be purchased upon such exercise;

&nbsp;&nbsp;&nbsp;&nbsp;· the designation and number of units of other securities purchasable upon the exercise of warrants to purchase other securities and
the price at which such number of units of such other securities may be purchased upon such exercise;

&nbsp;&nbsp;&nbsp;&nbsp;· the date on which the right to exercise such warrants will commence and the date on which such right will expire;

&nbsp;&nbsp;&nbsp;&nbsp;· U.S. federal income tax consequences applicable to such warrants;

&nbsp;&nbsp;&nbsp;&nbsp;· the number of warrants outstanding as of the most recent practicable date; and

&nbsp;&nbsp;&nbsp;&nbsp;· any other terms of such warrants.

Warrants will be issued in registered form only. The exercise price for warrants will be subject to adjustment in accordance with provisions described in the applicable prospectus supplement and/or other offering material.

Each warrant will entitle the holder thereof to purchase such principal amount of debt securities or such number of shares of preferred stock, common stock or other securities at such exercise price as will in each case be set forth in, or calculable from, the prospectus supplement and/or other offering material relating to the warrants, which exercise price may be subject to adjustment upon the occurrence of certain events as set forth in such prospectus supplement and/or other offering material. After the close of business on the expiration date, or such later date to which such expiration date may be extended by us, unexercised warrants will become void. The place or places where, and the manner in which, warrants may be exercised will be specified in the prospectus supplement and/or other offering material relating to such warrants.

Prior to the exercise of any warrants to purchase debt securities, preferred stock, common stock or other securities, holders of such warrants will not have any of the rights of holders of debt securities, preferred stock, common stock or other securities, as the case may be, purchasable upon such exercise, including the right to receive payments of principal of, premium, if any, or interest, if any, on the debt securities purchasable upon such exercise or to enforce covenants in the indenture, or to receive payments of dividends, if any, on the preferred stock, or common stock purchasable upon such exercise, or to exercise any applicable right to vote.

**Description of the Purchase Contracts and Purchase Units**

We may issue securities purchase contracts, including contracts obligating holders to purchase from us, and obligating us to sell to the holders, a specified number of shares of common stock or other securities at a future date or dates, which we refer to in this prospectus as "purchase contracts." The price per share of the securities and the number of shares of the securities may be fixed at the time the purchase contracts are issued or may be determined by reference to a specific formula set forth in the purchase contracts. The purchase contracts may be issued separately or as part of units consisting of a purchase contract and debt securities, preferred securities, warrants, other securities or debt obligations of third parties, including U.S. treasury securities, securing the holders' obligations to purchase the securities under the purchase contracts, which we refer to in this prospectus as "purchase units." The purchase contracts may require holders to secure their obligations under the purchase contracts in a specified manner. The purchase contracts also may require us to make periodic payments to the holders of the purchase units or vice versa, and those payments may be unsecured or refunded on some basis.

The purchase contracts, and, if applicable, collateral or depositary arrangements relating to the purchase contracts or purchase units, will be filed with the SEC in connection with the offering of purchase contracts or purchase units. The prospectus supplement and/or other offering material relating to a particular issue of purchase contracts or purchase units will describe the terms of those purchase contracts or purchase units, including the following:

&nbsp;&nbsp;&nbsp;&nbsp;· if applicable, a discussion of material U.S. federal income tax considerations; and

&nbsp;&nbsp;&nbsp;&nbsp;· any other information we think is important about the purchase contracts or the purchase units.

If we issue purchase units where debt obligations of third parties are used as security for your obligations to purchase or sell shares of common stock, preferred stock or other securities, we will include in the prospectus supplement and/or other offering material relating to the offering information about the issuer of the debt securities. Specifically, if the issuer has a class of securities registered under the Exchange Act, and is either eligible to register its securities on Form S-3 under the Securities Act or meets the listing criteria to be listed on a national securities exchange, we will include a brief description of the business of the issuer, the market price of its securities and how you can obtain more information about the issuer. If the issuer does not meet the criteria described in the previous sentence, we will include substantially all of the information that would be required if the issuer were making a public offering of the debt securities.

**Description of Units**

We may issue units comprised of two or more of the securities described in this prospectus, in any combination, including, without limitation, the purchase units described above. Each unit will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each included security. The units or the unit agreement or other agreement, if any, under which a unit is issued may provide that the securities included in the unit may not be held or transferred separately at any time, or at any time before a specified date.

The prospectus supplement relating to a particular issue of units will describe, among other things:

&nbsp;&nbsp;&nbsp;&nbsp;· the material terms of the units and of the securities comprising the units, including whether and under what circumstances those securities
may be held or transferred separately;

&nbsp;&nbsp;&nbsp;&nbsp;· any material provisions relating to the issuance, payment, settlement, transfer or exchange of the units or of the securities comprising
the units; and

&nbsp;&nbsp;&nbsp;&nbsp;· any material provisions of the governing unit or other agreement that differ from those described above.

**Where You Can Find More Information**

We file annual, quarterly and current reports, proxy statements and other information with the SEC (File No. 000-26966). We also filed a registration statement on Form S-3, including exhibits, under the Securities Act with respect to the securities offered by this prospectus. This prospectus is a part of that registration statement, but does not contain all of the information included in the registration statement or the exhibits to the registration statement. The SEC maintains a website, www.sec.gov, that contains reports, proxy and information statements and other information regarding issuers that file electronically with the SEC. Our SEC filings are also available to the public on our website located at www.advancedenergy.com. However, we are not including the information contained on our website as part of, or incorporating it by reference into, this prospectus.

We are "incorporating by reference" specified documents that we file with the SEC, which means:

&nbsp;&nbsp;&nbsp;&nbsp;· incorporated documents are considered part of this prospectus;

&nbsp;&nbsp;&nbsp;&nbsp;· we are disclosing important information to you by referring you to those documents; and

&nbsp;&nbsp;&nbsp;&nbsp;· information we file with the SEC will automatically update and supersede information contained in this prospectus.

We incorporate by reference the documents listed below and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this prospectus and before the end of the offering of the securities pursuant to this prospectus:

&nbsp;&nbsp;&nbsp;&nbsp;· our [Annual Report on Form 10-K for the year ended December 31, 2025](https://www.sec.gov/ix?doc=/Archives/edgar/data/927003/000110465926014731/aeis-20251231x10k.htm) ;

&nbsp;&nbsp;&nbsp;&nbsp;· our [Quarterly Report on Form 10-Q for the quarter ended March 31, 2026](https://www.sec.gov/ix?doc=/Archives/edgar/data/927003/000092700326000014/aeis-20260331x10q.htm) ;

&nbsp;&nbsp;&nbsp;&nbsp;· our Current Reports on Form 8-K filed on [May 4, 2026](https://www.sec.gov/ix?doc=/Archives/edgar/data/927003/000092700326000012/aeis-20260504x8k.htm) , [May 8, 2026](https://www.sec.gov/ix?doc=/Archives/edgar/data/927003/000110465926057731/tm2612734d2_8k.htm) , [May 13, 2026](https://www.sec.gov/ix?doc=/Archives/edgar/data/927003/000092700326000019/aeis-20260513x8k.htm) , [May 14, 2026](https://www.sec.gov/ix?doc=/Archives/edgar/data/927003/000110465926060543/aeis-20260513x8k.htm) and [May 18, 2026](https://www.sec.gov/ix?doc=/Archives/edgar/data/927003/000110465926063191/tm2612734d5_8k.htm) ; and

&nbsp;&nbsp;&nbsp;&nbsp;· The description of our common stock contained in our registration statement on Form 8-A, filed on October 12, 1995, including any
amendment or reports filed for the purpose of updating such description.

Notwithstanding the foregoing, information furnished under Items 2.02 and 7.01 of any Current Report on Form 8-K, including the related exhibits under Item 9.01, is not incorporated by reference.

You may request a copy of any of these filings, at no cost, by request directed to us at the following address or telephone number:

Advanced Energy Industries, Inc.<br> 1595 Wynkoop Street, Suite 800<br> Denver, Colorado 80202<br> 970-407-6626<br> Attention: General Counsel

You should not assume that the information in this prospectus, any prospectus supplement and/or other offering material, as well as the information we file or previously filed with the SEC that we incorporate by reference in this prospectus, any prospectus supplement and/or other offering material, is accurate as of any date other than its respective date. Our business, financial condition, results of operations and prospects may have changed since that date.

**Selling** Stockholders**

We may register shares of common stock covered by this prospectus for re-offers and resales by any selling stockholders to be named in a prospectus supplement. Because we are a well-known seasoned issuer, as defined in Rule 405 of the Securities Act, we may add secondary sales of shares of our common stock by any selling stockholders by filing a prospectus supplement with the SEC. We may register these shares to permit selling stockholders to resell their shares when they deem appropriate. A selling stockholder may resell all, a portion or none of such stockholder's shares at any time and from time to time. Selling stockholders may also sell, transfer or otherwise dispose of some or all of their shares of our common stock in transactions exempt from the registration requirements of the Securities Act. We do not know when or in what amounts the selling stockholders may offer shares for sale under this prospectus and any prospectus supplement. We may pay all expenses incurred with respect to the registration of the shares of common stock owned by the selling stockholders, other than underwriting fees, discounts or commissions, which will be borne by the selling stockholders. We will provide you with a prospectus supplement identifying the selling stockholders, the amount of shares to be registered and sold and any other terms of the shares of common stock being sold by each selling stockholder.

**Plan of Distribution**

We may sell our securities, and any selling stockholder may sell shares of our common stock, in any one or more of the following ways from time to time: (i) through agents; (ii) to or through underwriters; (iii) through brokers or dealers; (iv) directly by us or any selling stockholders to purchasers, including through a specific bidding, auction or other process; (v) in "at the market," equity line or similar offerings to or through a market maker or into an existing trading market, or a securities exchange or otherwise; (vi) through a combination of any of these methods of sale; or (vii) or through any other method permitted by applicable law and described in the applicable prospectus supplement. The applicable prospectus supplement and/or other offering material will contain the terms of the transaction, the name or names of any underwriters, dealers, or agents and the respective amounts of securities underwritten or purchased by them, the initial public offering price of the securities, and the applicable agent's commission, dealer's purchase price or underwriter's discount. Any selling stockholders, dealers and agents participating in the distribution of the securities may be deemed to be underwriters, and compensation received by them on resale of the securities may be deemed to be underwriting discounts. Additionally, because selling stockholders may be deemed to be "underwriters" within the meaning of Section 2(11) of the Securities Act, selling stockholders may be subject to the prospectus delivery requirements of the Securities Act.

Any initial offering price, dealer purchase price, discount or commission may be changed from time to time.

The securities may be distributed from time to time in one or more transactions, at negotiated prices, at a fixed price or fixed prices (that may be subject to change), at market prices prevailing at the time of sale, at various prices determined at the time of sale or at prices related to prevailing market prices.

Offers to purchase securities may be solicited directly by us or any selling stockholder or by agents designated by us from time to time. Any such agent may be deemed to be an underwriter, as that term is defined in the Securities Act, of the securities so offered and sold.

If underwriters are utilized in the sale of any securities in respect of which this prospectus is being delivered, such securities will be acquired by the underwriters for their own account and may be resold from time to time in one or more transactions, including negotiated transactions, at fixed public offering prices or at varying prices determined by the underwriters at the time of sale. Securities may be offered to the public either through underwriting syndicates represented by managing underwriters or directly by one or more underwriters. If any underwriter or underwriters are utilized in the sale of securities, unless otherwise indicated in the applicable prospectus supplement and/or other offering material, the obligations of the underwriters are subject to certain conditions precedent, and the underwriters will be obligated to purchase all such securities if they purchase any of them. Underwriters may be involved in any at the market offering of securities by or on our behalf.

If a dealer is utilized in the sale of the securities in respect of which this prospectus is delivered, we will sell such securities, and any selling stockholder will sell shares of our common stock to the dealer, as principal. The dealer may then resell such securities to the public at varying prices to be determined by such dealer at the time of resale. Transactions through brokers or dealers may include block trades in which brokers or dealers will attempt to sell shares as agent but may position and resell as principal to facilitate the transaction or in cross trades, in which the same broker or dealer acts as agent on both sides of the trade. Any such dealer may be deemed to be an underwriter, as such term is defined in the Securities Act, of the securities so offered and sold. In addition, any selling stockholder may sell shares of our common stock in ordinary brokerage transactions or in transactions in which a broker solicits purchases.

Offers to purchase securities may be solicited directly by us or any selling stockholder and the sale thereof may be made by us or any selling stockholder directly to institutional investors or others, who may be deemed to be underwriters within the meaning of the Securities Act with respect to any resale thereof.

Any selling stockholders may also resell all or a portion of their shares of our common stock in transactions exempt from the registration requirements of the Securities Act in reliance upon Rule 144 under the Securities Act provided they meet the criteria and conform to the requirements of that rule, Section 4(a)(1) of the Securities Act or other applicable exemptions, regardless of whether the securities are covered by the registration statement of which this prospectus forms a part.

If so indicated in the applicable prospectus supplement and/or other offering material, we or any selling stockholder may authorize agents and underwriters to solicit offers by certain institutions to purchase securities from us or any selling stockholder at the public offering price set forth in the applicable prospectus supplement and/or other offering material pursuant to delayed delivery contracts providing for payment and delivery on the date or dates stated in the applicable prospectus supplement and/or other offering material. Such delayed delivery contracts will be subject only to those conditions set forth in the applicable prospectus supplement and/or other offering material.

Agents, underwriters and dealers may be entitled under relevant agreements with us or any selling stockholder to indemnification by us against certain liabilities, including liabilities under the Securities Act, or to contribution with respect to payments which such agents, underwriters and dealers may be required to make in respect thereof. The terms and conditions of any indemnification or contribution will be described in the applicable prospectus supplement and/or other offering material. We may pay all expenses incurred with respect to the registration of the shares of common stock owned by any selling stockholders, other than underwriting fees, discounts or commissions, which will be borne by the selling stockholders.

We or any selling stockholder may also sell shares of our common stock through various arrangements involving mandatorily or optionally exchangeable securities, and this prospectus may be delivered in connection with those sales.

We or any selling stockholder may enter into derivative, sale or forward sale transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement and/or other offering material indicates, in connection with those transactions, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement and/or other offering material, including in short sale transactions and by issuing securities not covered by this prospectus but convertible into, or exchangeable for or representing beneficial interests in such securities covered by this prospectus, or the return of which is derived in whole or in part from the value of such securities. The third parties may use securities received under derivative, sale or forward sale transactions or securities pledged by us or any selling stockholder or borrowed from us, any selling stockholder or others to settle those sales or to close out any related open borrowings of stock, and may use securities received from us or any selling stockholder in settlement of those transactions to close out any related open borrowings of stock. The third party in such sale transactions will be an underwriter and will be identified in the applicable prospectus supplement (or a post-effective amendment) and/or other offering material.

Additionally, any selling stockholder may engage in hedging transactions with broker-dealers in connection with distributions of shares or otherwise. In those transactions, broker-dealers may engage in short sales of shares in the course of hedging the positions they assume with such selling stockholder. Any selling stockholder also may sell shares short and redeliver shares to close out such short positions. Any selling stockholder may also enter into option or other transactions with broker-dealers which require the delivery of shares to the broker-dealer. The broker-dealer may then resell or otherwise transfer such shares pursuant to this prospectus. Any selling stockholder also may loan or pledge shares, and the borrower or pledgee may sell or otherwise transfer the shares so loaned or pledged pursuant to this prospectus. Such borrower or pledgee also may transfer those shares to investors in our securities or the selling stockholder's securities or in connection with the offering of other securities not covered by this prospectus.

Underwriters, broker-dealers or agents may receive compensation in the form of commissions, discounts or concessions from us or any selling stockholder. Underwriters, broker-dealers or agents may also receive compensation from the purchasers of shares for whom they act as agents or to whom they sell as principals, or both. Compensation as to a particular underwriter, broker-dealer or agent will be in amounts to be negotiated in connection with transactions involving shares and might be in excess of customary commissions. In effecting sales, broker-dealers engaged by us or any selling stockholder may arrange for other broker-dealers to participate in the resales.

Any securities offered other than common stock will be a new issue and, other than the common stock, which is listed on the Nasdaq Global Select Market, will have no established trading market. We may elect to list any series of securities on an exchange, and in the case of the common stock, on any additional exchange, but, unless otherwise specified in the applicable prospectus supplement and/or other offering material, we shall not be obligated to do so. No assurance can be given as to the liquidity of the trading market for any of the securities.

Agents, underwriters and dealers may engage in transactions with, or perform services for, us or our subsidiaries or any selling stockholder in the ordinary course of business.

Any underwriter may engage in overallotment, stabilizing transactions, short covering transactions and penalty bids in accordance with Regulation M under the Exchange Act. Overallotment involves sales in excess of the offering size, which create a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum. Short covering transactions involve purchases of the securities in the open market after the distribution is completed to cover short positions. Penalty bids permit the underwriters to reclaim a selling concession from a dealer when the securities originally sold by the dealer are purchased in a covering transaction to cover short positions. Those activities may cause the price of the securities to be higher than it would otherwise be. If commenced, the underwriters may discontinue any of the activities at any time. An underwriter may carry out these transactions on the Nasdaq Global Select Market, in the over-the-counter market or otherwise.

The place and time of delivery for securities will be set forth in the accompanying prospectus supplement and/or other offering material for such securities.

**Legal Matters**

Unless the applicable prospectus supplement indicates otherwise, the validity of the securities offered by this prospectus will be passed upon for us by Foley & Lardner LLP. The validity of the securities offered by this prospectus will be passed upon for any underwriters or agents by counsel named in the applicable prospectus supplement. The opinions of Foley & Lardner LLP and counsel for any underwriters or agents may be conditioned upon and may be subject to assumptions regarding future action required to be taken by us and any underwriters, dealers or agents in connection with the issuance of any securities. The opinions of Foley & Lardner LLP and counsel for any underwriters or agents may be subject to other conditions and assumptions, as indicated in the prospectus supplement.

**Experts**

Ernst & Young LLP, independent registered public accounting firm, has audited our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2025, and the effectiveness of our internal control over financial reporting as of December 31, 2025, as set forth in their reports, which are incorporated by reference in this prospectus and elsewhere in the registration statement. Our financial statements are incorporated by reference in reliance on Ernst & Young LLP's reports, given on their authority as experts in accounting and auditing.

**PART II**

**INFORMATION NOT REQUIRED IN PROSPECTUS**

**Item 14. Other Expenses of Issuance and Distribution.**

The following table sets forth the estimated costs and expenses, other than underwriting discounts and commissions, payable by the registrant in connection with the offering of the securities being registered.

---

| | |
|:---|:---|
|  | **Amount** |
| Securities and Exchange Commission registration fee | $\* |
| Printing expenses | \*\* |
| Legal fees and expenses | \*\* |
| Accounting fees and expenses | \*\* |
| Blue sky filing and counsel fees | \*\* |
| Miscellaneous (including any applicable listing fees, rating agency fees, trustee and transfer agent's fees and expenses) | \*\* |
| &nbsp;&nbsp;&nbsp;Total | $\*\* |

---

\* Omitted because the SEC registration fee is being deferred in accordance with Rule 456(b) under the Securities Act and calculated in connection with the offering of securities under this registration statement pursuant to Rule 457(r) under the Securities Act.

\*\* The amount of securities and number of offerings are indeterminable, and the expenses cannot be estimated at this time.

**Item 15. Indemnification of Directors and Officers.**

*Delaware General Corporation Law*

As a Delaware corporation, we are subject to the provisions of the General Corporation Law of the State of Delaware (the "Delaware General Corporation Law"). Section 145(a) of the Delaware General Corporation Law provides that a corporation may indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of the corporation) by reason of the fact that the person is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, against expenses (including attorneys' fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by the person in connection with such action, suit or proceeding if the person acted in good faith and in a manner the person reasonably believed to be in or not opposed to the best interests of the corporation, and, with respect to any criminal action or proceeding, had no reasonable cause to believe the person's conduct was unlawful. The termination of any action, suit or proceeding by judgment, order, settlement, conviction or upon a plea of nolo contendere or its equivalent, shall not, of itself, create a presumption that the person did not act in good faith and in a manner which the person reasonably believed to be in or not opposed to the best interests of the corporation, and, with respect to any criminal action or proceeding, had reasonable cause to believe that the person's conduct was unlawful.

Section 145(b) of the Delaware General Corporation Law states that a corporation may indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action or suit by or in the right of the corporation to procure a judgment in its favor by reason of the fact that the person is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise against expenses (including attorneys' fees) actually and reasonably incurred by the person in connection with the defense or settlement of such action if the person acted in good faith and in a manner the person reasonably believed was in or not opposed to the best interests of the corporation and except that no indemnification shall be made in respect of any claim, issue or matter as to which the person shall have been adjudged to be liable to the corporation unless and only to the extent that the Delaware Court of Chancery or the court in which such action or suit was brought shall determine upon application that, despite the adjudication of liability but in view of all the circumstances of the case, the person is fairly and reasonably entitled to indemnity for such expenses as the Delaware Court of Chancery or such other court shall deem proper.

Section 145(c) of the Delaware General Corporation Law provides that to the extent that a present or former director or officer of a corporation has been successful on the merits or otherwise in defense of any action, suit or proceeding referred to in subsections (a) and (b) of Section 145, or in defense of any claim, issue or matter therein, such person shall be indemnified against expenses (including attorneys' fees) actually and reasonably incurred by such person in connection therewith.

Section 145(d) of the Delaware General Corporation Law states that any indemnification under subsections (a) and (b) of Section 145 (unless ordered by a court) shall be made by the corporation only as authorized in the specific case upon a determination that indemnification of the present or former director, officer, employee or agent is proper in the circumstances because the person has met the applicable standard of conduct set forth in subsections (a) and (b) of Section 145. Such determination shall be made with respect to a person who is a director or officer at the time of such determination (1) by a majority vote of the directors who are not parties to such action, suit or proceeding, even though less than a quorum, (2) by a committee of such directors designated by majority vote of such directors, even though less than a quorum, (3) if there are no such directors, or if such directors so direct, by independent legal counsel in a written opinion or (4) by the stockholders.

Section 145(f) of the Delaware General Corporation Law states that the indemnification and advancement of expenses provided by, or granted pursuant to, the other subsections of Section 145 shall not be deemed exclusive of any other rights to which those seeking indemnification or advancement of expenses may be entitled under any by-law, agreement, vote of stockholders or disinterested directors or otherwise, both as to action in such person's official capacity and as to action in another capacity while holding such office. A right to indemnification or to advancement of expenses arising under a provision of the certificate of incorporation or a by-law shall not be eliminated or impaired by an amendment to the certificate of incorporation or the by-laws after the occurrence of the act or omission that is the subject of the civil, criminal, administrative or investigative action, suit or proceeding for which indemnification or advancement of expenses is sought, unless the provision in effect at the time of such act or omission explicitly authorizes such elimination or impairment after such action or omission has occurred.

Section 145(g) of the Delaware General Corporation Law provides that a corporation shall have the power to purchase and maintain insurance on behalf of any person who is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, against any liability asserted against such person and incurred by such person in any such capacity or arising out of such person's status as such, whether or not the corporation would have the power to indemnify such person against such liability under the provisions of Section 145 of the Delaware General Corporation Law.

Section 145(j) of the Delaware General Corporation Law states that the indemnification and advancement of expenses provided by, or granted pursuant to, Section 145 shall, unless otherwise provided when authorized or ratified, continue as to a person who has ceased to be a director, officer, employee or agent and shall inure to the benefit of the heirs, executors and administrators of such a person.

*Certificate of Incorporation*

Our Certificate of Incorporation provides that no director or officer of Advanced Energy shall be personally liable to the company or its stockholders for monetary damages for any breach of fiduciary duty as a director or officer, except for liability of (i) a director or officer for any breach of the director's or officer's duty of loyalty to the company or its stockholders, (ii) a director or officer for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (iii) a director under Section 174 of the Delaware General Corporation Law, (iv) a director or officer for any transaction from which the director or officer derived an improper personal benefit, or (v) an officer in any action by or in the right of Advanced Energy. While the Certificate of Incorporation provides protection from awards for monetary damages for breaches of the duty of care, it does not eliminate the director's or officer's duty of care. Accordingly, the Certificate of Incorporation will not affect the availability of equitable remedies such as an injunction based on a director's or officer's breach of the duty of care.

*By-laws*

Our By-laws provide for the indemnification of our executive officers and directors to the fullest extent not prohibited by the Delaware General Corporation Law; provided, however, that we may modify the extent of such indemnification by individual contracts with our executive officers and directors; and, provided further, that we shall not be required to indemnify any director or executive officer in connection with any proceeding (or part thereof) initiated by such person unless: (i) such indemnification is expressly required to be made by law; (ii) the proceeding was authorized by our board of directors; (iii) such indemnification is provided by us, in our sole discretion, pursuant to the powers vested in Advanced Energy under the Delaware General Corporation Law; or (iv) such indemnification is required to be made under Article XI, Section 43, Subsection (d) of our By-laws. Expenses for the defense of any action for which indemnification may be available may be advanced by us under certain circumstances.

*Indemnification Agreements*

We have entered into indemnity agreements with each of the members of our board of directors and each of our executive officers. Pursuant to such indemnity agreements, we are required to indemnify each such person to the fullest extent permitted by the Delaware General Corporation Law against any liability incurred by such person in any proceeding in which such person is a party because he or she is a director or executive officer of Advanced Energy.

*Other Insurance*

We maintain a directors' and officers' insurance policy pursuant to which our directors and officers are insured against liability for actions taken in their capacities as directors and officers, including liabilities under the Securities Act.

**Item 16. Exhibits.**

The following is a list of all exhibits filed as part of this Registration Statement on Form S-3.

---

| | |
|:---|:---|
| **EXHIBIT INDEX** | **EXHIBIT INDEX** |
| Exhibit <br> <u>Number</u> | <br> <u>Document Description</u> |
| 1.1 | Form of Equity Underwriting Agreement.<sup>1</sup> |
| 1.2 | Form of Debt Underwriting Agreement.<sup>1</sup> |
| [4.1](https://www.sec.gov/Archives/edgar/data/927003/000155837019007077/aeis-20190630ex311a9cf04.htm) | [Amended and Restated Certificate of Incorporation (incorporated by reference to Exhibit 3.1 to Advanced Energy's Quarterly Report on Form 10-Q filed August 5, 2019).](https://www.sec.gov/Archives/edgar/data/927003/000155837019007077/aeis-20190630ex311a9cf04.htm) |
| [4.2](https://www.sec.gov/Archives/edgar/data/927003/000155837019007077/aeis-20190630ex311a9cf04.htm) | [Articles of Amendment to Amended and Restated Certificate of Incorporation (incorporated by reference to Exhibit 3.1 to Advanced Energy's Current Report on Form 8-K filed May 8, 2026).](https://www.sec.gov/Archives/edgar/data/927003/000155837019007077/aeis-20190630ex311a9cf04.htm) |
| [4.3](https://www.sec.gov/Archives/edgar/data/927003/000155837020006867/aeis-20200519xex3d1.htm) | [Third Amended and Restated By-laws (incorporated by reference to Exhibit 3.2 to Advanced Energy's Current Report on Form 8-K dated May 1, 2024).](https://www.sec.gov/Archives/edgar/data/927003/000155837020006867/aeis-20200519xex3d1.htm) |
| [4.4](https://www.sec.gov/Archives/edgar/data/927003/000155837023001501/tmb-20230217xex4d3.htm) | [Form of Indenture (incorporated by reference to Exhibit 4.3 to Advanced Energy's Registration Statement on Form S-3 filed on February 17, 2023).](https://www.sec.gov/Archives/edgar/data/927003/000155837023001501/tmb-20230217xex4d3.htm) |
| 4.5 | Form of Debt Securities.<sup>1</sup> |
| 4.6 | Form of Warrant.<sup>1</sup> |
| 4.7 | Form of Warrant Agreement.<sup>1</sup> |
| 4.8 | Form of Purchase Contract.<sup>1</sup> |
| [51](tm2612734d1_ex5-1.htm) | [Opinion of Foley & Lardner LLP (including consent of counsel).](tm2612734d1_ex5-1.htm) |
| [23.1](tm2612734d1_ex23-1.htm) | [Consent of Independent Registered Public Accounting Firm.](tm2612734d1_ex23-1.htm) |
| [23.2](tm2612734d1_ex5-1.htm) | [Consent of Foley & Lardner LLP (included in Exhibit 5.1).](tm2612734d1_ex5-1.htm) |
| [24](#a_016) | [Power of Attorney (included on signature page).](#a_016) |
| 25 | Form T-1 Statement of Eligibility and Qualification under the Trust Indenture Act of 1939 (with respect to the indenture). <sup>2</sup> |
| [107](tm2612734d1_ex-filingfees.htm) | [Filing Fee Exhibit.](tm2612734d1_ex-filingfees.htm) |

---

<sup>1</sup> If required, to be filed by amendment or as an exhibit to a Current Report on Form 8-K and incorporated herein by reference. <br> <sup>2</sup> To be filed in accordance with the requirements of Section 305(b)(2) of the Trust Indenture Act of 1939 and Rule 5b-3 thereunder.

**Item 17. Undertakings.**

The undersigned registrant hereby undertakes:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i) To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Securities and Exchange Commission (the "Commission") pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the "Calculation of Registration Fee" table in the effective registration statement; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

*provided, however,* that paragraphs (i), (ii) and (iii) of this section do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d) That, for the purpose of determining liability under the Securities Act of 1933 to any purchaser:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i) Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ii) Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5) or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii) or (x) for the purpose of providing the information required by Section 10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. *Provided, however,* that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(e) That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i) Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ii) Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(iii) The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(iv) Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant's annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan's annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Commission such indemnification is against public policy as expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933 and will be governed by the final adjudication of such issue.

The undersigned registrant hereby undertakes to file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act of 1939 in accordance with the rules and regulations prescribed by the Commission under Section 305(b)(2) of the Trust Indenture Act of 1939.

**SIGNATURES**

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Denver, State of Colorado, on June 10, 2026.

---

| | |
|:---|:---|
| ADVANCED ENERGY INDUSTRIES, INC. | ADVANCED ENERGY INDUSTRIES, INC. |
| By: | /s/ Elizabeth K. Vonne |
|  | Elizabeth K. Vonne |
|  | *Executive Vice President, General Counsel, and Corporate Secretary* |

---

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities indicated on June 10, 2026. Each person whose signature appears below constitutes and appoints Paul Oldham and Elizabeth K. Vonne, and each of them individually, his or her true and lawful attorney-in-fact and agent, with full power of substitution and revocation, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or either of them, may lawfully do or cause to be done by virtue hereof.

---

| | |
|:---|:---|
| &nbsp;&nbsp;**<u>Signature</u>** | &nbsp;&nbsp;**<u>Title</u>** |
| &nbsp;&nbsp;/s/ Stephen D. Kelley | &nbsp;&nbsp;Chief Executive Officer and Director |
| &nbsp;&nbsp;Stephen D. Kelley | &nbsp;&nbsp;(Principal Executive Officer) |
| &nbsp;&nbsp;/s/ Paul Oldham | &nbsp;&nbsp;Chief Financial Officer and Executive Vice President |
| &nbsp;&nbsp;Paul Oldham | &nbsp;&nbsp;(Principal Financial Officer) |
| &nbsp;&nbsp;/s/ Bernard R. Colpitts, Jr. | &nbsp;&nbsp;Chief Accounting Officer and Senior Vice President |
| &nbsp;&nbsp;Bernard R. Colpitts, Jr. | &nbsp;&nbsp;(Principal Accounting Officer) |
| &nbsp;&nbsp;/s/ Grant H. Beard | &nbsp;&nbsp;Chairman of the Board |
| &nbsp;&nbsp;Grant H. Beard |  |
| &nbsp;&nbsp;/s/ Frederick A. Ball | &nbsp;&nbsp;Director |
| &nbsp;&nbsp;Frederick A. Ball |  |
| &nbsp;&nbsp;/s/ Anne T. DelSanto | &nbsp;&nbsp;Director |
| &nbsp;&nbsp;Anne T. DelSanto |  |
| &nbsp;&nbsp;/s/ Tina M. Donikowski | &nbsp;&nbsp;Director |
| &nbsp;&nbsp;Tina M. Donikowski |  |
| &nbsp;&nbsp;/s/ Ronald C. Foster | &nbsp;&nbsp;Director |
| &nbsp;&nbsp;Ronald C. Foster |  |
| &nbsp;&nbsp;/s/ Lanesha T. Minnix | &nbsp;&nbsp;Director |
| &nbsp;&nbsp;Lanesha T. Minnix |  |
| &nbsp;&nbsp; /s/ David W. Reed | &nbsp;&nbsp;Director |
| &nbsp;&nbsp;David W. Reed |  |
| &nbsp;&nbsp;/s/ John A. Roush | &nbsp;&nbsp;Director |
| &nbsp;&nbsp;John A. Roush |  |
| &nbsp;&nbsp;/s/ Brian M. Shirley | &nbsp;&nbsp;Director |
| &nbsp;&nbsp;Brian M. Shirley |  |

---

## Exhibit 5.1

**Exhibit 5.1**

---

| | |
|:---|:---|
| ![](tm2612734d1_ex5-1img001.jpg) | **ATTORNEYS AT LAW**<br>777 EAST WISCONSIN AVENUE<br> MILWAUKEE, WI 53202-5306<br> 414.271.2400 TEL<br> 414.297.4900 FAX<br> WWW.FOLEY.COM |

---

June 10, 2026

Advanced Energy Industries, Inc.

1595 Wynkoop Street, Suite 800

Denver, Colorado 80202

Re: Registration Statement on Form S-3

Ladies and Gentlemen:

In connection with the Registration Statement on Form S-3 (the "<u>Registration Statement</u>") under the Securities Act of 1933, as amended (the "<u>Securities Act</u>"), of Advanced Energy Industries, Inc., a Delaware corporation (the "<u>Company</u>"), proposed to be filed by the Company with the Securities and Exchange Commission (the "<u>Commission</u>") on or about the date hereof, you have requested our opinions set forth below.

You have provided us with a copy of the Registration Statement, which relates to (1) the issuance and sale from time to time, pursuant to Rule 415 of the General Rules and Regulations of the Commission promulgated under the Securities Act (the "<u>Rules and Regulations</u>"), of an indeterminate amount of any of the following: (i) debt securities of the Company (the "<u>Debt Securities</u>"); (ii) shares of the Company's common stock, par value $0.001 per share (the "<u>Common Stock</u>"); (iii) shares of the Company's preferred stock, par value $0.001 per share (the "<u>Preferred Stock</u>"); (iv) warrants to purchase securities of the Company (the "<u>Warrants</u>"); (v) contracts to purchase shares of Common Stock or other securities of the Company (the "<u>Purchase Contracts</u>"); (vi) units, each comprised of a Purchase Contract and either debt obligations or other securities of the Company or debt obligations of third parties securing the holder's obligation to purchase securities under the Purchase Contract (the "<u>Purchase Units</u>"); and (vii) units of the Company, each consisting of any interest in two or more securities of the types described in the Registration Statement, or a combination thereof (the "<u>Units</u>" and, together with the Debt Securities, the Common Stock, the Preferred Stock, the Warrants, the Purchase Contracts and the Purchase Units, the "<u>Securities</u>"). The Prospectus provides that it will be supplemented in the future by one or more supplements to such Prospectus and/or other offering material (each, a "<u>Prospectus Supplement</u>").

We understand that (i) any Units may be issued pursuant to one or more unit agreements (each, a "<u>Unit Agreement</u>") between the Company and the unit agent named therein ("<u>Unit Agent</u>") substantially in the form to be filed as an exhibit to a post-effective amendment to the Registration Statement or as an exhibit to a document filed under the Securities Exchange Act of 1934, as amended (the "<u>Exchange Act</u>"), and incorporated into the Registration Statement by reference; (ii) any Debt Securities will be issued in one or more series pursuant to an indenture for Debt Securities substantially in the form of exhibit 4.4 to the Registration Statement (the "<u>Indenture</u>"), between the Company, the registrar named therein (the "<u>Registrar</u>") and the trustee named therein (the "<u>Trustee</u>"); and (iii) any Warrants may be issued pursuant to one or more warrant agreements (each, a "<u>Warrant Agreement</u>") between the Company and the warrant agent named therein (the "<u>Warrant Agent</u>") substantially in the form to be filed as an exhibit to a post-effective amendment to the Registration Statement or as an exhibit to a document filed under the Exchange Act and incorporated into the Registration Statement by reference. As used herein, "<u>Transaction Agreements</u>" means the Unit Agreements, the Indenture, the Warrant Agreements, the Purchase Contracts and the Purchase Units.

AUSTIN \| BOSTON \| BRUSSELS \| CHICAGO \| DALLAS \| DENVER \| DETROIT \| HOUSTON \| JACKSONVILLE \| LOS ANGELES

MADISON \| MEXICO CITY \| MIAMI \| MILWAUKEE \| NASHVILLE \| NEW YORK \| ORLANDO \| RALEIGH \| SACRAMENTO

\| SALT LAKE CITY \| SAN DIEGO \| SAN FRANCISCO \| SILICON VALLEY \| TALLAHASSEE \| TAMPA \| TOKYO \| WASHINGTON, D.C.

![](tm2612734d1_ex5-1img001.jpg)

June 10, 2026

In connection with this opinion, we have examined (i) the Registration Statement, including the prospectus constituting a part thereof and the exhibits thereto (including those incorporated by reference), each constituting a part of the Registration Statement; (ii) the Company's Amended and Restated Certificate of Incorporation, as amended to date ("<u>Certificate of Incorporation</u>"), and the Company's Third Amended and Restated By-Laws ("<u>Bylaws</u>"); (iii) the Indenture; (iv) resolutions of the Board of Directors of the Company relating to the registration of the Securities; and (v) originals or copies, certified or otherwise identified to our satisfaction, of such records, agreements and instruments of the Company, certificates and receipts of public officials and of officers or other representatives of the Company, and such other documents and records, and such matters of law, as we have deemed necessary or appropriate as a basis for the opinions stated below. In our examination, we have assumed the genuineness of all manual and electronic signatures, including endorsements, the legal capacity and competency of all natural persons, the authenticity of all documents submitted to us as originals and the conformity to the original documents of all documents submitted to us as facsimile, electronic, certified or photostatic copies, and the authenticity of the originals of such copies. As to various questions of fact material to this opinion, we have relied upon, without independent verification of their accuracy, certificates of public officials, statements and representations of officers and other representatives of the Company, and statements of fact contained in documents we have examined.

The opinions expressed herein presume that all of the following (collectively, the "<u>general conditions</u>") shall have occurred prior to the issuance of the Securities referred to therein: (i) the Registration Statement, and any amendments thereto (including post-effective amendments), will comply with the Securities Act and the applicable Rules and Regulations and has become effective under the Securities Act; (ii) an appropriate prospectus supplement with respect to such Securities offered thereby will have been prepared, delivered and filed in compliance with the Securities Act and the applicable Rules and Regulations; (iii) all Securities will be issued and sold in compliance with applicable federal and state securities laws and in the manner stated in the Registration Statement and any applicable prospectus supplement; (iv) the applicable Transaction Agreements shall have been duly authorized, executed and delivered by the Company and the other parties thereto, including, if such Securities are to be sold or otherwise distributed pursuant to an underwritten offering, the underwriting agreement or purchase agreement with respect thereto; (v) the issuance and sale of such Securities (and the terms and conditions thereof) have been duly authorized and approved on behalf of the Company; (vi) the terms of the applicable Transaction Agreements and the issuance and sale of such Securities have been duly established in conformity with the requisite organizational documents of the Company, so as not to violate any applicable law, or any of its organizational documents, or result in a default under or breach of any agreement or instrument binding upon the Company, so as to comply with any requirement or restriction imposed by any court or governmental body having jurisdiction over the Company, the Warrant Agent, the Unit Agent, the Trustee, and the Registrar, as applicable; (vii) a Form T-1 will be filed with the Commission with respect to the trustee executing any indenture or any supplemental indenture to such indenture; (viii) any Securities issuable upon conversion, exchange or exercise of any Security being offered will have been duly authorized, created and, if appropriate, reserved for issuance upon such conversion, exchange or exercise and (ix) with respect to shares of Common Stock or Preferred Stock offered, there will be sufficient shares of Common Stock or Preferred Stock authorized under the Certificate of Incorporation and not otherwise reserved for issuance.

![](tm2612734d1_ex5-1img001.jpg)

June 10, 2026

Based upon the foregoing and subject to the qualifications and assumptions stated herein, we are of the opinion that:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1. Each series of Debt Securities will be valid and binding obligations of the Company enforceable in accordance with their terms, when (a) the general conditions shall have been satisfied, (b) the Indenture shall have been qualified under the Trust Indenture Act of 1939, as amended (the "<u>TIA</u>"), and a Form T-1 shall have been filed with the Commission and become effective under the TIA with respect to the trustee executing the Indenture or any related supplemental indenture, (c) the Indenture (and any related supplemental indenture) shall have been duly executed and delivered by the Company, the Trustee, and the Registrar, as applicable, and (d) such series of Debt Securities shall have been (i) duly executed by the Company, authenticated by the Trustee as provided in the Indenture and issued by the Company and (ii) issued and sold or otherwise distributed in accordance with the provisions of the applicable Indenture (and any related supplemental indenture) and, if distributed pursuant to an underwritten offering, in accordance with the provisions of the underwriting agreement or purchase agreement with respect thereto, and upon payment of the agreed-upon consideration therefor.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2. With respect to any shares of the Common Stock offered by the Company pursuant to the Registration Statement (the "<u>Offered Common Stock</u>"), when (a) the general conditions shall have been satisfied, (b) if the Offered Common Stock is to be certificated, certificates in the form required under the Delaware General Corporation Law ("<u>DGCL</u>") representing the shares of Offered Common Stock are duly executed and countersigned, and (c) the shares of Offered Common Stock are registered in the Company's share registry and delivered upon payment of the agreed-upon consideration therefor, the shares of Offered Common Stock, when issued and sold or otherwise distributed in accordance with the provisions of the applicable Transaction Agreements and, if distributed pursuant to an underwritten offering, in accordance with the provisions of the underwriting agreement or purchase agreement with respect thereto, will be duly authorized by all requisite corporate action on the part of the Company under the DGCL and validly issued, fully paid and nonassessable, provided that the consideration therefor is not less than the par value per share of the Common Stock.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3. With respect to any shares of the Preferred Stock offered by the Company pursuant to the Registration Statement (the "<u>Offered Preferred Stock</u>"), when (a) the general conditions shall have been satisfied, (b) the Board of Directors of the Company, or a duly authorized committee thereof, has duly adopted a Certificate of Designations to the Company's Certificate of Incorporation establishing voting powers, designations, preferences and relative, participating, optional or other special rights, if any, or the qualifications, limitations or restrictions, if any, and other terms of such shares of the Offered Preferred Stock, as set forth in or contemplated by the Registration Statement, the exhibits thereto and any prospectus supplement relating to such Preferred Stock, in accordance with the DGCL, (c) such Certificate of Designations to the Company's Certificate of Incorporation with respect to any such shares of Offered Preferred Stock shall have been duly filed with and accepted for record by the Secretary of State of the State of Delaware in the form and manner required by law, (d) if the Offered Preferred Stock is to be certificated, certificates in the form required under the DGCL representing the shares of Offered Preferred Stock are duly executed and countersigned, and (e) the shares of Offered Preferred Stock are registered in the Company's share registry and delivered upon payment of the agreed-upon consideration therefor, the shares of Offered Preferred Stock, when issued and sold or otherwise distributed in accordance with the provisions of the applicable Transaction Agreements and, if distributed pursuant to an underwritten offering, in accordance with the provisions of the underwriting agreement or purchase agreement with respect thereto, will be duly authorized by all requisite corporate action on the part of the Company under the DGCL and validly issued, fully paid and nonassessable, provided that the consideration therefor is not less than the par value per share of the Preferred Stock.

![](tm2612734d1_ex5-1img001.jpg)

June 10, 2026

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;4. With respect to any Warrants offered by the Company pursuant to the Registration Statement (the "<u>Offered Warrants</u>"), when (a) the general conditions shall have been satisfied, (b) the shares of Common Stock, shares of Preferred Stock or other securities described in the Registration Statement for which the Offered Warrants are exercisable have been duly authorized for issuance by the Company, (c) the terms of the Offered Warrants have been established in accordance with the Warrant Agreement (if any), and (d) the Offered Warrants have been duly executed (if certificated) and delivered in accordance with the provisions of the applicable Warrant Agreement (if any), the Offered Warrants, when issued and sold or otherwise distributed in accordance with the provisions of the applicable Warrant Agreement (if any) and, if distributed pursuant to an underwritten offering, in accordance with the provisions of the underwriting agreement or purchase agreement with respect thereto, and upon payment of the agreed-upon consideration therefor, will constitute valid and binding obligations of the Company, enforceable against the Company in accordance with their respective terms under the laws of the State of New York.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5. With respect to any Purchase Contracts and Purchase Units offered by the Company pursuant to the Registration Statement (the "<u>Offered Purchase Agreements</u>"), when (a) the general conditions shall have been satisfied, (b) the shares of Common Stock, shares of Preferred Stock, or Debt Securities included in such Offered Purchase Agreements have been duly authorized for issuance by the Company, (c) the terms of the Common Stock, Preferred Stock, or Debt Securities included in the Offered Purchase Agreements have been established in accordance with the applicable Offered Purchase Agreements, and (d) the Offered Purchase Agreements have been duly executed and delivered in accordance with the provisions of thereof, the Offered Purchase Agreements, when issued and sold or otherwise distributed in accordance with the provisions of the applicable Purchase Contracts or Purchase Units and, if distributed pursuant to an underwritten offering, in accordance with the provisions of the underwriting agreement or purchase agreement with respect thereto, and upon payment of the agreed-upon consideration therefor, will constitute valid and binding obligations of the Company, enforceable against the Company in accordance with their respective terms under the laws of the State of New York.

![](tm2612734d1_ex5-1img001.jpg)

June 10, 2026

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6. With respect to any Units offered by the Company pursuant to the Registration Statement (the "<u>Offered Units</u>"), when (a) the general conditions shall have been satisfied, (b) the shares of Common Stock, shares of Preferred Stock, Purchase Contracts, Debt Securities, Warrants, or other securities or a combination thereof included in such Offered Units have been duly authorized for issuance by the Company, (c) the terms of the Offered Units have been established in accordance with the applicable Unit Agreement (if any), and (d) the Offered Units have been duly executed (if certificated) and delivered in accordance with the provisions of the applicable Unit Agreement (if any), the Offered Units, when issued and sold or otherwise distributed in accordance with the provisions of the applicable Unit Agreement (if any) and, if distributed pursuant to an underwritten offering, in accordance with the provisions of the underwriting agreement or purchase agreement with respect thereto, and upon payment of the agreed-upon consideration therefor, will constitute valid and binding obligations of the Company, enforceable against the Company in accordance with their respective terms under the laws of the State of New York.

We express no opinion herein as to the laws of any state or jurisdiction other than the State of New York, the applicable provisions of the DGCL and the federal laws of the United States of America. Notwithstanding the foregoing, we express no opinion as to the applicability or effect of any state securities laws, including the securities laws of the States of Delaware and New York, or as to state laws regarding fraudulent transfers. To the extent that any matter as to which our opinion is expressed herein would be governed by the laws of any jurisdiction other than those set forth above in this paragraph, we do not express any opinion on such matter.

The opinions stated herein are subject to the following qualifications:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) the opinions stated herein are limited by applicable bankruptcy, insolvency, reorganization, moratorium, fraudulent transfer, preference and other similar laws affecting creditors' rights generally, and by general principles of equity (regardless of whether enforcement is sought in equity or at law);

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) we do not express any opinion with respect to any law, rule or regulation that is applicable to any party to any of the Transaction Agreements or the transactions contemplated thereby solely because such law, rule or regulation is part of a regulatory regime applicable to any such party or any of its affiliates as a result of the specific assets or business operations of such party or such affiliates;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c) except to the extent expressly stated in the opinions contained herein, we have assumed that each of the Transaction Agreements constitutes the valid and binding obligation of each party to such Transaction Agreement, enforceable against such party in accordance with its terms;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d) to the extent relevant to our opinions in paragraphs 1, 4, 5, and 6, and not covered by our opinions in paragraphs 2 or 3, we have assumed that any securities, currencies or commodities underlying, comprising or issuable upon exchange, conversion or exercise of any Purchase Contracts, Purchase Units, Units, Debt Securities, or Warrants are validly issued, fully paid and nonassessable (in the case of an equity security) or a legal, valid and binding obligation of the issuer thereof, enforceable against such issuer in accordance with its terms; and

![](tm2612734d1_ex5-1img001.jpg)

June 10, 2026

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(e) we have assumed that any Purchase Contracts, Units, Debt Securities, Warrants and Purchase Units that may be issued will be manually authenticated, signed or countersigned, as the case may be, by duly authorized officers of any Warrant Agent, Unit Agent, Registrar and Trustee, as the case may be.

In addition, in rendering the foregoing opinions we have assumed that:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(x) neither the execution and delivery by the Company of the Transaction Agreements nor the performance by the Company of its obligations thereunder, including the issuance and sale of the applicable Securities: (i) constitutes or will constitute a violation of, or a default under, any lease, indenture, instrument or other agreement to which the Company, or its property is subject, (ii) contravened or will contravene any order or decree of any governmental authority to which the Company or its property is subject, or (iii) except to the extent expressly stated in the opinions contained herein, violates or will violate any law, rule or regulation to which the Company or its property is subject;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(y) neither the execution and delivery by the Company of the Transaction Agreements nor the performance by the Company of its obligations thereunder, including the issuance and sale of the applicable Securities, requires or will require the consent, approval, licensing or authorization of, or any filing, recording or registration with, any governmental authority under any law, rule or regulation of any jurisdiction; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(z) the validity, construction, and enforceability of the Transaction Agreements will be governed by the laws of the State of New York.

This opinion is being furnished to you for submission to the Commission as an exhibit to the Registration Statement in accordance with the requirements of Item 16 of Form S-3 and Item 601(b)(5) of Regulation S-K promulgated under the Securities Act. We hereby consent to the filing of this opinion as Exhibit 5.1 to the Registration Statement with the Commission on the date hereof and to the use of the name of our firm in the section entitled "Legal Matters" in the Registration Statement. In giving this consent, we do not admit that we are within the category of persons whose consent is required by Section 7 of the Securities Act or the rules and regulations promulgated thereunder by the Commission.

This opinion is limited to the matters stated in this letter, and no opinion may be implied or inferred beyond the matters expressly stated in this letter. This opinion is given as of the date hereof, and we assume no obligation to advise you after the date hereof of facts or circumstances that come to our attention or changes in the law, including judicial or administrative interpretations thereof, that occur which could affect the opinions contained herein. This opinion may not be used for any other purpose without our written consent, which we may grant or withhold in our sole discretion.

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| Very truly yours, |
| /s/ Foley & Lardner LLP |
| Foley & Lardner LLP |

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## Exhibit 23.1

**Exhibit 23.1**

**Consent of Independent Registered Public Accounting Firm**

We consent to the reference to our firm under the caption "Experts" in this Registration Statement (Form S-3) and related Prospectus of Advanced Energy Industries, Inc. for the registration of its debt securities, common stock, preferred stock, warrants, purchase contracts, purchase units, and units and to the incorporation by reference therein of our reports dated February 13, 2026, with respect to the consolidated financial statements of Advanced Energy Industries, Inc., and the effectiveness of internal control over financial reporting of Advanced Energy Industries, Inc., included in its Annual Report (Form 10-K) for the year ended December 31, 2025, filed with the Securities and Exchange Commission.

/s/ Ernst & Young LLP

Denver, Colorado<br> June 10, 2026

## Ex-Filing

?xml version='1.0' encoding='ASCII'? EX-FILING FEES

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| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Calculation of Filing Fee Tables**  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **S-3**  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **ADVANCED ENERGY INDUSTRIES INC**  |

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| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
| | | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Security Type**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Security Class Title**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Fee Calculation or Carry Forward Rule**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Maximum Aggregate Offering Price**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Fee Rate**  | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Amount of Registration Fee**  |
| **Newly Registered Securities** | **Newly Registered Securities** | **Newly Registered Securities** | **Newly Registered Securities** | **Newly Registered Securities** | **Newly Registered Securities** | **Newly Registered Securities** | **Newly Registered Securities** |
| Fees to be Paid | 1 | Debt | Debt Securities | 457(r) |  | 0.0001381 |  |
| Fees to be Paid | 2 | Equity | Common Stock, par value $0.001 per share | 457(r) |  | 0.0001381 |  |
| Fees to be Paid | 3 | Equity | Preferred Stock, par value $0.001 per shar | 457(r) |  | 0.0001381 |  |
| Fees to be Paid | 4 | Other | Warrants | 457(r) |  | 0.0001381 |  |
| Fees to be Paid | 5 | Other | Purchase Contracts | 457(r) |  | 0.0001381 |  |
| Fees to be Paid | 6 | Other | Purchase Units | 457(r) |  | 0.0001381 |  |
| Fees to be Paid | 7 | Other | Units | 457(r) |  | 0.0001381 |  |
| Fees Previously Paid |  |  |  |  |  |  |  |
| **Carry Forward Securities** | **Carry Forward Securities** | **Carry Forward Securities** | **Carry Forward Securities** | **Carry Forward Securities** | **Carry Forward Securities** | **Carry Forward Securities** | **Carry Forward Securities** |
| Carry Forward Securities |  |  |  |  |  |  |  |
|  |  |  | Total Offering Amounts: | Total Offering Amounts: | $0.00  |  | $0.00  |
|  |  |  | Total Fees Previously Paid:  | Total Fees Previously Paid:  |  |  | $0.00  |
|  |  |  | Total Fee Offsets:  | Total Fee Offsets:  |  |  | $0.00  |
|  |  |  | Net Fee Due:  | Net Fee Due:  |  |  | $0.00  |

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&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **Offering Note** <br>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <sup>1</sup> Any securities registered hereunder may be sold separately or as units with other securities registered hereunder. Separate consideration may or may not be received for securities that are issuable on exercise, conversion, or exchange of other securities. In accordance with Rules 456(b) and 457(r) under the Securities Act of 1933, as amended, the registrant is deferring payment of all of the registration fee. In connection with the securities offered hereby, the registrant will pay "pay-as-you-go registration fees" in accordance with Rule 456(b). The registrant will calculate the registration fee applicable to an offer of securities pursuant to this registration statement based on the fee payment rate in effect on the date of such fee payment. An indeterminate aggregate offering price or number of securities of each identified class is being registered as may from time to time be offered at indeterminate prices.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <sup>2</sup> See Footnote

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <sup>3</sup> See Footnote

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <sup>4</sup> See Footnote

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <sup>5</sup> See Footnote

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <sup>6</sup> See Footnote

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <sup>7</sup> See Footnote

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| **Rules 457(b) and 0-11(a)(2)** |
| Fee Offset Claims |
| Fee Offset Sources |
| **Rule 457(p)** |
| Fee Offset Claims |
| Fee Offset Sources |

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