IDEXX (IDXX) CEO sells 23,326 shares after major option exercise

Rhea-AI Filing Summary

IDEXX Laboratories President and CEO Jonathan Jay Mazelsky exercised stock options for 23,523 shares of common stock at exercise prices of $141.6000 and $505.5300. He then sold 23,326 shares in multiple open-market trades at prices including $650.6695 and $663.0439, ending with 83,803.302 shares held directly.

SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

MAZELSKY JONATHAN JAY

(Last) (First) (Middle)

ONE IDEXX DRIVE

(Street)

WESTBROOK ME 04092

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
IDEXX LABORATORIES INC /DE [ IDXX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President and CEO

3. Date of Earliest Transaction (Month/Day/Year)
02/26/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	02/26/2026		M		23,326	A	$141.6	106,932.302	D
Common Stock	02/26/2026		S		1,281	D	$650.6695(1)	105,651.302	D
Common Stock	02/26/2026		S		1,095	D	$651.4866(2)	104,556.302	D
Common Stock	02/26/2026		S		1,669	D	$652.4945(3)	102,887.302	D
Common Stock	02/26/2026		S		1,171	D	$653.6763(4)	101,716.302	D
Common Stock	02/26/2026		S		1,111	D	$654.6294(5)	100,605.302	D
Common Stock	02/26/2026		S		1,488	D	$655.8498(6)	99,117.302	D
Common Stock	02/26/2026		S		1,343	D	$656.8451(7)	97,774.302	D
Common Stock	02/26/2026		S		2,860	D	$657.8438(8)	94,914.302	D
Common Stock	02/26/2026		S		3,660	D	$658.9166(9)	91,254.302	D
Common Stock	02/26/2026		S		2,859	D	$659.7495(10)	88,395.302	D
Common Stock	02/26/2026		S		1,200	D	$661.0976(11)	87,195.302	D
Common Stock	02/26/2026		S		1,000	D	$662.1567(12)	86,195.302	D
Common Stock	02/26/2026		S		2,589	D	$663.0439(13)	83,606.302	D
Common Stock	02/27/2026		M		197	A	$505.53	83,803.302	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Non-Qualified Stock Option (right-to-buy)	$141.6	02/26/2026		M			23,326	(14)	02/13/2027	Common Stock	23,326	$0	0	D
Incentive Stock Option (right-to-buy)	$505.53	02/27/2026		M			197	(15)	02/13/2032	Common Stock	197	$0	0	D

Explanation of Responses:

1. Represents the weighted average price of the shares sold ranging from a low of $650.00 to a high of $650.96 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price.

2. Represents the weighted average price of the shares sold ranging from a low of $651.06 to a high of $651.85 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price.

3. Represents the weighted average price of the shares sold ranging from a low of $652.105 to a high of $653.06 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price.

4. Represents the weighted average price of the shares sold ranging from a low of $653.19 to a high of $654.155 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price.

5. Represents the weighted average price of the shares sold ranging from a low of $654.24 to a high of $655.2175 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price.

6. Represents the weighted average price of the shares sold ranging from a low of $655.275 to a high of $656.205 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price.

7. Represents the weighted average price of the shares sold ranging from a low of $656.28 to a high of $657.27 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price.

8. Represents the weighted average price of the shares sold ranging from a low of $657.305 to a high of $658.275 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price.

9. Represents the weighted average price of the shares sold ranging from a low of $658.30 to a high of $659.24 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price.

10. Represents the weighted average price of the shares sold ranging from a low of $659.31 to a high of $660.275 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price.

11. Represents the weighted average price of the shares sold ranging from a low of $660.59 to a high of $661.55 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price.

12. Represents the weighted average price of the shares sold ranging from a low of $661.65 to a high of $662.55 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price.

13. Represents the weighted average price of the shares sold ranging from a low of $662.72 to a high of $663.505 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price.

14. Grant of option to buy shares of Issuer common stock that vested in five annual installments beginning February 14, 2018.

15. Grant of option to buy shares of Issuer common stock that vested on February 14, 2026.

Remarks:

	/s/ Lily J. Lu, Attorney-in-Fact for Jonathan Jay Mazelsky	03/02/2026
	** Signature of Reporting Person	Date
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).
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FAQ

What insider transactions did IDEXX (IDXX) report for its CEO?

IDEXX reported that CEO Jonathan Jay Mazelsky exercised stock options for 23,523 common shares and sold 23,326 shares in multiple open-market transactions. These moves adjusted his directly held stake but did not eliminate his ownership position.

How many IDEXX (IDXX) shares did the CEO sell and at what prices?

Jonathan Jay Mazelsky sold 23,326 IDEXX common shares in a series of open-market trades. Individual transactions show sale prices such as $650.6695 and $663.0439 per share, with footnotes noting weighted-average prices across narrow intraday ranges.

How many IDEXX (IDXX) shares does the CEO hold after these Form 4 transactions?

After exercising options and selling shares, CEO Jonathan Jay Mazelsky directly holds 83,803.302 IDEXX common shares. This balance reflects option exercises on February 26–27, 2026 and subsequent open-market sales disclosed in the Form 4 filing.

What stock options did the IDEXX (IDXX) CEO exercise in this Form 4?

Mazelsky exercised an Incentive Stock Option for 197 shares and a Non-Qualified Stock Option for 23,326 shares. Footnotes state these options were grants to buy IDEXX common stock that vested in annual installments beginning February 14, 2018 and on February 14, 2026.

Were the IDEXX (IDXX) CEO’s transactions open-market buys or option exercises?

The Form 4 shows option exercises followed by sales. Code “M” transactions reflect exercising derivative securities into common stock, while code “S” entries represent open-market or private sales of IDEXX common shares at the disclosed per-share prices.