Thermo Fisher (NYSE: TMO) CFO reports tax-withholding of company shares

Rhea-AI Filing Summary

Thermo Fisher Scientific executive Stephen Williamson reported tax-related share dispositions. On February 28, 2026, he used two blocks of Common Stock, totaling 921.793 shares (674.724 and 247.069 shares), to satisfy tax obligations at a price of $521.11 per share, classified as tax-withholding dispositions rather than open-market sales.

After these transactions, Williamson held 32,499.4000 shares of Common Stock directly. He also reported 12,674.0000 shares held indirectly "By SLAT," with a footnote stating he disclaims beneficial ownership of indirectly owned securities except to the extent of any pecuniary interest.

Insights

Equity compensation and governance analyst

Reported transactions are routine tax-withholding, not open-market selling.

The transactions involve code F, which indicates shares were withheld to pay tax liabilities tied to equity awards. This means no discretionary sale decision in the open market, which typically makes these events less informative about the insider’s view on the stock.

After the withholding, Stephen Williamson still directly holds 32,499.4000 Common Stock shares. An additional 12,674.0000 shares are held indirectly by a SLAT, with beneficial ownership disclaimed except for any pecuniary interest. Overall, this looks like standard equity-compensation administration rather than a thesis-changing move.

Insider Trade Summary

Net Seller: 921.793 shares

Net Sell 3 txns

Insider Williamson Stephen

Role Retiring Sr. VP and CFO

Type	Security	Shares	Price	Value
Exercise Price or Tax Liability	Common Stock	674.724	$521.11	$352K
Exercise Price or Tax Liability	Common Stock	247.069	$521.11	$129K
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 32,499.4 shares (Direct); Common Stock — 12,674 shares (Indirect, By SLAT)

Footnotes (1)

1. F1. The reporting person disclaims beneficial ownership of the securities reported herein as indirectly beneficially owned, except to the extent of any pecuniary interest therein.

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Form 4 Insider Transactions: What Each Field Means →

Accepted by SEC EDGAR 03/02/2026 - 04:04 PM Learn about SEC filing dates

FAQ

What did Thermo Fisher (TMO) executive Stephen Williamson report in this Form 4?

Stephen Williamson reported using company Common Stock to cover tax liabilities on February 28, 2026. Two tax-withholding dispositions totaling 921.793 shares were executed at $521.11 per share, and his updated direct and indirect holdings were disclosed.

Were the Thermo Fisher (TMO) transactions by Stephen Williamson open-market stock sales?

No, the Form 4 shows code F transactions, meaning tax-withholding dispositions, not open-market sales. Shares were delivered to satisfy tax obligations related to equity awards, a common administrative step in executive compensation programs.

How many Thermo Fisher (TMO) shares does Stephen Williamson hold after these transactions?

After the reported dispositions, Stephen Williamson directly holds 32,499.4000 shares of Thermo Fisher Common Stock. He also reports 12,674.0000 shares held indirectly by a SLAT, with beneficial ownership disclaimed except for any pecuniary interest.

What does the SLAT reference mean in Stephen Williamson’s Thermo Fisher (TMO) Form 4?

The Form 4 lists 12,674.0000 Common Stock shares held indirectly "By SLAT." A footnote states he disclaims beneficial ownership of indirectly owned securities, except to the extent of any pecuniary interest, indicating these shares are held through a trust-like structure.

How many Thermo Fisher (TMO) shares were used for tax withholding by Stephen Williamson?

The filing shows two tax-withholding dispositions totaling 921.793 Common Stock shares. One transaction covered 674.724 shares and the other 247.069 shares, both priced at $521.11 per share, to satisfy tax liabilities related to equity compensation.

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

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

X

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^*

Williamson Stephen

(Last) (First) (Middle)

168 THIRD AVENUE

(Street)

WALTHAM MA 02451

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
THERMO FISHER SCIENTIFIC INC. [ TMO ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Retiring Sr. VP and CFO

3. Date of Earliest Transaction (Month/Day/Year)
02/28/2026

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	02/28/2026		F		674.724	D	$521.11	32,746.469	D
Common Stock	02/28/2026		F		247.069	D	$521.11	32,499.4	D
Common Stock								12,674	I	By SLAT(1)

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

Explanation of Responses:

1. The reporting person disclaims beneficial ownership of the securities reported herein as indirectly beneficially owned, except to the extent of any pecuniary interest therein.

	/s/ Melodie T. Morin, Attorney-in-Fact for Stephen Williamson	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).
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.