# EDGAR Filing Document

**Accession Number:** 0002135522
**File Stem:** 0001049502-26-000103
**Filing Date:** 2026-6
**Character Count:** 8322
**Document Hash:** bfa98753f9cbb378dbe189b7da2a6da7
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001049502-26-000103.hdr.sgml**: 20260604

**ACCESSION NUMBER**: 0001049502-26-000103

**CONFORMED SUBMISSION TYPE**: 3

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20260601

**FILED AS OF DATE**: 20260604

**DATE AS OF CHANGE**: 20260604

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Donlan Renee Martel
- **CENTRAL INDEX KEY:** 0002135522

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 3
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 000-23621
- **FILM NUMBER:** 261064393

**MAIL ADDRESS:**
- **STREET 1:** 2 TECH DRIVE
- **CITY:** ANDOVER
- **STATE:** MA
- **ZIP:** 01810
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MKS INC
- **CENTRAL INDEX KEY:** 0001049502
- **STANDARD INDUSTRIAL CLASSIFICATION:** INDUSTRIAL INSTRUMENTS FOR MEASUREMENT, DISPLAY, AND CONTROL [3823]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 042277512
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 2 TECH DRIVE
- **CITY:** ANDOVER
- **STATE:** MA
- **ZIP:** 01810
- **BUSINESS PHONE:** 978-645-5500

**MAIL ADDRESS:**
- **STREET 1:** 2 TECH DRIVE
- **CITY:** ANDOVER
- **STATE:** MA
- **ZIP:** 01810

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MKS INSTRUMENTS INC
- **DATE OF NAME CHANGE:** 19971112

## Ex-24

```

							Exhibit 24

LIMITED POWER OF ATTORNEY FOR SECTION 16 REPORTING OBLIGATIONS

Know all by these present that the undersigned hereby constitutes
and appoints each of M. Kathryn Rickards, James Kruger and
Saba Habte, signing singly, the undersigned's true and lawful
attorney-in-fact to:

1)	execute for and on behalf of the undersigned, in the
undersigned's capacity as an officer and/or director of MKS Inc.
(the "Company"), Forms 3, 4, 5 and  144 (collectively, the ?Forms?)
in accordance with Section 16(a) of the Securities Exchange Act
of 1934 and the rules thereunder;

2)	do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to complete and
execute any such Forms, complete and execute any amendment or
amendments thereto, and timely file such Forms with the United
States Securities and Exchange Commission and any stock exchange
or similar authority; and

3)	take any other action of any type whatsoever in connection
with the foregoing which, in the opinion of such attorney-in-fact,
may be of benefit to, in the best interest of, or legally required by,
the undersigned, it being understood that the documents executed by
such attorney-in-fact on behalf of the undersigned pursuant to this
Limited Power of Attorney shall be in such form and shall contain such
terms and conditions as such attorney-in-fact may approve in such
attorney-in-fact's discretion.

The undersigned hereby grants to each such attorney-in-fact full power
and authority to do and perform any and every act and thing whatsoever
requisite, necessary, or proper to be done in the exercise of any of
the rights and powers herein granted, as fully to all intents and
purposes as the undersigned might or could do if personally present,
with full power of substitution or revocation, hereby ratifying and
confirming all that such attorney-in-fact, or such attorney-in-fact's
substitute or substitutes, shall lawfully do or cause to be done by
virtue of this Limited Power of Attorney and the rights and powers
herein granted.  The undersigned acknowledges that the foregoing
attorneys-in-fact, in serving in such capacity at the request of
the undersigned, are not assuming, nor is the Company assuming,
any of the undersigned's responsibilities to comply with Section
16 of the Securities Exchange Act of 1934.

This Limited Power of Attorney shall supersede any power of attorney
previously granted by the undersigned with respect to the subject
matter herein and shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4, 5 and 144
with respect to the undersigned's holdings of and transactions in
securities issued by the Company, unless earlier revoked by the
undersigned in a signed writing delivered to the foregoing
attorneys-in-fact. This Limited Power of Attorney may be filed
with the SEC as a confirming statement of the authority
granted herein.

IN WITNESS WHEREOF, the undersigned has caused this Limited Power
of Attorney to be executed as of this 1st day of June 2026.

/s/ Renee M. Donlan
_________________________
Renee M. Donlan

```

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 3

### INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Donlan Renee Martel<br><sub>(Last) (First) (Middle)</sub><br>C/O MKS INC.<br>2 TECH DRIVE<br><sub>(Street)</sub><br>ANDOVER, MA 01810<br><sub>(City) (State) (Zip)</sub> | **3. Issuer Name and Ticker or Trading Symbol**<br>MKS INC [ MKSI ] | **5. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  |
| **2. Date of Event Requiring Statement (Month/Day/Year)**<br>2026-06-01 | **4. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director   [ ] 10% Owner<br>[X] Officer (give title below)   [ ] Other (specify below)<br>_EVP, GC & CCO_ | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities Beneficially Owned

---

|  |  |  |  |
| --- | --- | --- | --- |
| 1. Title of Security | 2. Amount of Securities Beneficially Owned | 3. Ownership Form | 4. Nature of Indirect Beneficial Ownership |
| Common Stock | 9471.7084 | D |  |

---

## Table II - Derivative Securities Beneficially Owned

---

|  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 3. Title and Amount of Underlying Securities | 3. Title and Amount of Underlying Securities | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| Restricted Stock Unit | <sup>(1)</sup> | <sup>(1)</sup> | Common Stock | 415.813 | <sup>(2)</sup> | D |  |
| Restricted Stock Unit | <sup>(3)</sup> | <sup>(3)</sup> | Common Stock | 2481.346 | <sup>(2)</sup> | D |  |
| Restricted Stock Unit | <sup>(4)</sup> | <sup>(4)</sup> | Common Stock | 929.368 | <sup>(2)</sup> | D |  |

---

### Footnotes:

(1) These restricted stock units (RSUs) vest on April 15, 2027.

(2) Each RSU represents the contingent right to receive one share of common stock of MKS Inc.

(3) These RSUs vest in two equal annual installments commencing on April 15, 2027, provided that if, in any vesting year, April 15th is not a business day, such vesting shall occur on the next business day.

(4) These RSUs vest in three equal annual installments commencing on April 15, 2027, provided that if, in any vesting year, April 15th is not a business day, such vesting shall occur on the next business day.

**Remarks:**
Exhibit 24 - Power of Attorney

**Signature:** /s/ M. Kathryn Rickards, attorney-in-fact  
**Date:** 2026-06-04

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**