Form990-PF

Department of the Treasury
Internal Revenue Service

Return of Private Foundation
or Section 4947(a)(1) Trust Treated as Private Foundation
right arrowDo not enter social security numbers on this form as it may be made public.
right arrowGo to www.irs.gov/Form990PF for instructions and the latest information.
OMB No. 1545-0047
2024
Open to Public Inspection
For calendar year 2024, or tax year beginning 01-01-2024 , and ending 12-31-2024
Name of foundation
The Thorne Cox Family Foundation
C/O Brown Advisory
Number and street (or P.O. box number if mail is not delivered to street address)100 High Street 27th Floor
  Room/suite
City or town, state or province, country, and ZIP or foreign postal code
Boston, MA02110
A Employer identification number

46-4274950
B Telephone number (see instructions)

(617) 717-6373
C right arrow
G Check all that apply:

D 1. Foreign organizations, check here............. right arrow
2. Foreign organizations meeting the 85%
test, check here and attach computation ... right arrow
E right arrow
H Check type of organization:
F right arrow
I Fair market value of all assets at end
of year (from Part II, col. (c),
line 16)right arrow$4,293,422J Accounting method:
 
(Part I, column (d) must be on cash basis.)
Part I Analysis of Revenue and Expenses (The total of amounts in columns (b), (c), and (d) may not necessarily equal the amounts in column (a) (see instructions).) (a) Revenue and
expenses per
books 		(b) Net investment
income 		(c) Adjusted net
income 		(d) Disbursements
for charitable
purposes
(cash basis only)
Revenue 1 Contributions, gifts, grants, etc., received (attach schedule)  
2 Check right arrow.............
3 Interest on savings and temporary cash investments      
4 Dividends and interest from securities... 69,189 69,092  
5a Gross rents............      
b Net rental income or (loss)  
6a Net gain or (loss) from sale of assets not on line 10 381,510
b Gross sales price for all assets on line 6a 1,091,252
7 Capital gain net income (from Part IV, line 2)... 839,099
8 Net short-term capital gain.........  
9 Income modifications...........  
10a Gross sales less returns and allowances  
b Less: Cost of goods sold....  
c Gross profit or (loss) (attach schedule).....    
11 Other income (attach schedule)....... Click to see attachment
List of Attached Documents:
// Content
121,955 32,261  
12 Total. Add lines 1 through 11........ 572,654 940,452  
Operating and Administrative Expenses 13 Compensation of officers, directors, trustees, etc. 0 0   0
14 Other employee salaries and wages......        
15 Pension plans, employee benefits.......        
16a Legal fees (attach schedule).........        
b Accounting fees (attach schedule)....... Click to see attachment
List of Attached Documents:
// Content
11,000 11,000   0
c Other professional fees (attach schedule).... Click to see attachment
List of Attached Documents:
// Content
1,799 1,799   0
17 Interest............... 2,344 2,344   0
18 Taxes (attach schedule) (see instructions)... Click to see attachment
List of Attached Documents:
// Content
12,275 1,267   0
19 Depreciation (attach schedule) and depletion...      
20 Occupancy..............        
21 Travel, conferences, and meetings.......        
22 Printing and publications..........        
23 Other expenses (attach schedule)....... Click to see attachment
List of Attached Documents:
// Content
55,961 55,207   265
24 Total operating and administrative expenses.
Add lines 13 through 23.......... 83,379 71,617   265
25 Contributions, gifts, grants paid....... 572,149 572,149
26 Total expenses and disbursements. Add lines 24 and 25 655,528 71,617   572,414
27 Subtract line 26 from line 12:
a Excess of revenue over expenses and disbursements -82,874
b Net investment income (if negative, enter -0-) 868,835
c Adjusted net income (if negative, enter -0-)...  
For Paperwork Reduction Act Notice, see instructions.
Cat. No. 11289X Form 990-PF (2024)
Form 990-PF (2024)
Page 2
Part II Balance Sheets Attached schedules and amounts in the description column
should be for end-of-year amounts only. (See instructions.) 		Beginning of year End of year
(a) Book Value (b) Book Value (c) Fair Market Value
Assets 1 Cash—non-interest-bearing.............      
2 Savings and temporary cash investments......... 59,603 166,588 166,588
3 Accounts receivable right arrow  
Less: allowance for doubtful accounts right arrow        
4 Pledges receivable right arrow  
Less: allowance for doubtful accounts right arrow        
5 Grants receivable.................      
6 Receivables due from officers, directors, trustees, and other
disqualified persons (attach schedule) (see instructions).....      
7 Other notes and loans receivable (attach schedule) right arrow  
Less: allowance for doubtful accounts right arrow        
8 Inventories for sale or use..............      
9 Prepaid expenses and deferred charges..........      
10a Investments—U.S. and state government obligations (attach schedule)      
b Investments—corporate stock (attach schedule)....... 308,444 0 0
c Investments—corporate bonds (attach schedule).......      
11 Investments—land, buildings, and equipment: basis right arrow  
Less: accumulated depreciation (attach schedule) right arrow        
12 Investments—mortgage loans.............      
13 Investments—other (attach schedule).......... 3,624,653 Click to see attachment
List of Attached Documents:
// Content
4,101,834 		4,101,834
14 Land, buildings, and equipment: basis right arrow  
Less: accumulated depreciation (attach schedule) right arrow        
15 Other assets (describe right arrow) Click to see attachment
List of Attached Documents:
// Content
0 		Click to see attachment
List of Attached Documents:
// Content
25,000 		Click to see attachment
List of Attached Documents:
// Content
25,000
16 Total assets (to be completed by all filers—see the
instructions. Also, see page 1, item I) 3,992,700 4,293,422 4,293,422
Liabilities 17 Accounts payable and accrued expenses..........    
18 Grants payable.................    
19 Deferred revenue.................    
20 Loans from officers, directors, trustees, and other disqualified persons    
21 Mortgages and other notes payable (attach schedule)......    
22 Other liabilities (describe right arrow)    
23 Total liabilities (add lines 17 through 22)......... 0 0
Net Assets or Fund Balances Foundations that follow FASB ASC 958, check here right arrow
and complete lines 24, 25, 29 and 30.
24 Net assets without donor restrictions........... 3,992,700 4,293,422
25 Net assets with donor restrictions............    
Foundations that do not follow FASB ASC 958, check here right arrow
and complete lines 26 through 30.
26 Capital stock, trust principal, or current funds........    
27 Paid-in or capital surplus, or land, bldg., and equipment fund    
28 Retained earnings, accumulated income, endowment, or other funds    
29 Total net assets or fund balances (see instructions)..... 3,992,700 4,293,422
30 Total liabilities and net assets/fund balances (see instructions). 3,992,700 4,293,422
Part III
Analysis of Changes in Net Assets or Fund Balances
1
Total net assets or fund balances at beginning of year—Part II, column (a), line 29 (must agree with end-of-year figure reported on prior year’s return) ...............
1
3,992,700
2
Enter amount from Part I, line 27a .....................
2
-82,874
3
Other increases not included in line 2 (itemize) right arrowClick to see attachment
List of Attached Documents:
// Content
3
383,678
4
Add lines 1, 2, and 3 ..........................
4
4,293,504
5
Decreases not included in line 2 (itemize) right arrowClick to see attachment
List of Attached Documents:
// Content
5
82
6
Total net assets or fund balances at end of year (line 4 minus line 5)—Part II, column (b), line 29 .
6
4,293,422
Form 990-PF (2024)
Form 990-PF (2024)
Page 3
Part IV
Capital Gains and Losses for Tax on Investment Income
(a) List and describe the kind(s) of property sold (e.g., real estate,
2-story brick warehouse; or common stock, 200 shs. MLC Co.)		 (b)
How acquired
P—Purchase
D—Donation 		(c)
Date acquired
(mo., day, yr.) 		(d)
Date sold
(mo., day, yr.)
1 a Morris Foundation, LLC K-1 LT Gain/Loss - UBI P    
b Morris Foundation, LLC K-1 1231 Gain/Loss - UBI P    
c Morris Foundation, LLC K-1 ST Gain/Loss - UBI P    
d Morris Foundation, LLC K-1 1231 Gain/Loss - UBI P    
e Morris Foundation, LLC K-1 LT Gain/Loss - UBI P    
Morris Foundation, LLC K-1 ST Gain/Loss - UBI P    
Publicly Traded Securities      
Morris Foundation, LLC K-1 LT Capital Distribution P    
(e)
Gross sales price 		(f)
Depreciation allowed
(or allowable) 		(g)
Cost or other basis
plus expense of sale 		(h)
Gain or (loss)
(e) plus (f) minus (g)
a 523   523 0
b       0
c       0
d 366     366
e 316,594     316,594
2,756     2,756
764,931   251,630 513,301
6,082     6,082
Complete only for assets showing gain in column (h) and owned by the foundation on 12/31/69 (l)
Gains (Col. (h) gain minus
col. (k), but not less than -0-) or
Losses (from col.(h))
(i)
F.M.V. as of 12/31/69 		(j)
Adjusted basis
as of 12/31/69 		(k)
Excess of col. (i)
over col. (j), if any
a       0
b       0
c       0
d       366
e       316,594
      2,756
      513,301
      6,082
2 Capital gain net income or (net capital loss) Bracket If gain, also enter in Part I, line 7
If (loss), enter -0- in Part I, line 7		 Bracket 2 839,099
3 Net short-term capital gain or (loss) as defined in sections 1222(5) and (6):
If gain, also enter in Part I, line 8, column (c) (see instructions). If (loss), enter -0-
in Part I, line 8 ................... 		Bracket 3  
Part V
Excise Tax Based on Investment Income (Section 4940(a), 4940(b), 4940(e), or 4948—see instructions)
1a Exempt operating foundations described in section 4940(d)(2), check here right arrow and enter “N/A" on line 1. Bracket for line 1a
Date of ruling or determination letter:   (attach copy of letter if necessary–see instructions) 1 12,077
b All other domestic foundations enter 1.39% (0.0139) of line 27b. Exempt foreign organizations enter 4% (0.04) of Part I, line 12, col. (b)
2 Tax under section 511 (domestic section 4947(a)(1) trusts and taxable foundations only. Others enter -0-) 2 0
3 Add lines 1 and 2........................... 3 12,077
4 Subtitle A (income) tax (domestic section 4947(a)(1) trusts and taxable foundations only. Others enter -0-) 4 0
5 Tax based on investment income. Subtract line 4 from line 3. If zero or less, enter -0- ..... 5 12,077
6 Credits/Payments:
a 2024 estimated tax payments and 2023 overpayment credited to 2024 6a 17,058
b Exempt foreign organizations—tax withheld at source...... 6b 0
c Tax paid with application for extension of time to file (Form 8868)... 6c 0
d Backup withholding erroneously withheld .......... 6d 0
7 Total credits and payments. Add lines 6a through 6d.............. 7 17,058
8 Enter any penalty for underpayment of estimated tax. Check here if Form 2220 is attached. Click to see attachment
List of Attached Documents:
// Content
8 0
9 Tax due. If the total of lines 5 and 8 is more than line 7, enter amount owed.......right arrow 9  
10 Overpayment. If line 7 is more than the total of lines 5 and 8, enter the amount overpaid...right arrow 10 4,981
11 Enter the amount of line 10 to be: Credited to 2025 estimated taxright arrow4,981 Refundedright arrow 11 0
Form 990-PF (2024)
Form 990-PF (2024)
Page 4
Part VI-A
Statements Regarding Activities
1a
During the tax year, did the foundation attempt to influence any national, state, or local legislation or did
Yes
No
it participate or intervene in any political campaign? ....................
1a
 
No
b
Did it spend more than $100 during the year (either directly or indirectly) for political purposes? See the instructions
for the definition.................................
1b
 
No
If the answer is "Yes" to 1a or 1b, attach a detailed description of the activities and copies of any materials
published or distributed by the foundation in connection with the activities.
c
Did the foundation file Form 1120-POL for this year?.....................
1c
 
No
d
Enter the amount (if any) of tax on political expenditures (section 4955) imposed during the year:
(1) On the foundation. right arrow$ 0(2) On foundation managers.right arrow$ 0
e
Enter the reimbursement (if any) paid by the foundation during the year for political expenditure tax imposed
on foundation managers.right arrow$ 0
2
Has the foundation engaged in any activities that have not previously been reported to the IRS?.......
2
 
No
If "Yes," attach a detailed description of the activities.
3
Has the foundation made any changes, not previously reported to the IRS, in its governing instrument, articles
of incorporation, or bylaws, or other similar instruments? If "Yes," attach a conformed copy of the changes....
3
 
No
4a
Did the foundation have unrelated business gross income of $1,000 or more during the year?.........
4a
Yes
 
b
If "Yes," has it filed a tax return on Form 990-T for this year?...................
4b
Yes
 
5
Was there a liquidation, termination, dissolution, or substantial contraction during the year?.........
5
 
No
If "Yes," attach the statement required by General Instruction T.
6
Are the requirements of section 508(e) (relating to sections 4941 through 4945) satisfied either:
round bullet By language in the governing instrument, or
round bullet By state legislation that effectively amends the governing instrument so that no mandatory directions
that conflict with the state law remain in the governing instrument? ................
6
Yes
 
7
Did the foundation have at least $5,000 in assets at any time during the year? If "Yes," complete Part II, col. (c),
and Part XIV..................................
7
Yes
 
8a
Enter the states to which the foundation reports or with which it is registered (see instructions)
right arrowFL
b
If the answer is "Yes" to line 7, has the foundation furnished a copy of Form 990-PF to the Attorney
General (or designate) of each state as required by General Instruction G? If "No," attach explanation .
8b
Yes
 
9
Is the foundation claiming status as a private operating foundation within the meaning of section 4942(j)(3)
or 4942(j)(5) for calendar year 2024 or the taxable year beginning in 2024? See the instructions for Part XIII.
If "Yes," complete Part XIII .............................
9
 
No
10
Did any persons become substantial contributors during the tax year? If "Yes," attach a schedule listing their names
and addresses. ...............................
10
 
No
11
At any time during the year, did the foundation, directly or indirectly, own a controlled entity within the
meaning of section 512(b)(13)? If "Yes," attach schedule. See instructions .............
11
 
No
12
Did the foundation make a distribution to a donor advised fund over which the foundation or a disqualified person had
advisory privileges? If "Yes," attach statement. See instructions.................
12
 
No
13
Did the foundation comply with the public inspection requirements for its annual returns and exemption application?
13
Yes
 
Website addressright arrowN/A
14
The books are in care ofright arrowDune Thorne Telephone no.right arrow (617) 717-6373

Located atright arrow100 High Street 27th FloorBostonMA ZIP+4right arrow02110
15
Section 4947(a)(1) nonexempt charitable trusts filing Form 990-PF in lieu of Form 1041 —check here .........right arrow
and enter the amount of tax-exempt interest received or accrued during the year ........right arrow
15
 
16 At any time during calendar year 2024, did the foundation have an interest in or a signature or other authority over YesNo
a bank, securities, or other financial account in a foreign country? .................
16   No
See the instructions for exceptions and filing requirements for FinCEN Form 114. If "Yes", enter the name of the foreign
country right arrow
Form 990-PF (2024)
Form 990-PF (2024)
Page 5
Part VI-B
Statements Regarding Activities for Which Form 4720 May Be Required
File Form 4720 if any item is checked in the "Yes" column, unless an exception applies.
Yes
No
1a
During the year did the foundation (either directly or indirectly):
(1) Engage in the sale or exchange, or leasing of property with a disqualified person? ...........
1a(1)
 
No
(2) Borrow money from, lend money to, or otherwise extend credit to (or accept it from)
a disqualified person? ..............................
1a(2)
 
No
(3) Furnish goods, services, or facilities to (or accept them from) a disqualified person? ...........
1a(3)
 
No
(4) Pay compensation to, or pay or reimburse the expenses of, a disqualified person? ............
1a(4)
 
No
(5) Transfer any income or assets to a disqualified person (or make any of either available
for the benefit or use of a disqualified person)? ......................
1a(5)
 
No
(6) Agree to pay money or property to a government official? (Exception. Check "No"
if the foundation agreed to make a grant to or to employ the official for a period
after termination of government service, if terminating within 90 days.) ...............
1a(6)
 
No
b
If any answer is "Yes" to 1a(1)–(6), did any of the acts fail to qualify under the exceptions described in Regulations
section 53.4941(d)-3 or in a current notice regarding disaster assistance? See instructions ..........
1b
 
 
c
Organizations relying on a current notice regarding disaster assistance check here ........right arrow
d
Did the foundation engage in a prior year in any of the acts described in 1a, other than excepted acts,
that were not corrected before the first day of the tax year beginning in 2024? .............
1d
 
No
2
Taxes on failure to distribute income (section 4942) (does not apply for years the foundation was a private
operating foundation defined in section 4942(j)(3) or 4942(j)(5)):
a
At the end of tax year 2024, did the foundation have any undistributed income (Part XII, lines 6d
and 6e) for tax year(s) beginning before 2024?....................
2a
 
No
If "Yes," list the years right arrow20, 20, 20, 20
b
Are there any years listed in 2a for which the foundation is not applying the provisions of section 4942(a)(2)
(relating to incorrect valuation of assets) to the year’s undistributed income? (If applying section 4942(a)(2)
to all years listed, answer "No" and attach statement—see instructions.) ..............
2b
 
 
c
If the provisions of section 4942(a)(2) are being applied to any of the years listed in 2a, list the years here.
right arrow20, 20, 20, 20
3a
Did the foundation hold more than a 2% direct or indirect interest in any business enterprise at
any time during the year? ..............................
3a
 
No
b
If "Yes," did it have excess business holdings in 2024 as a result of (1) any purchase by the foundation
or disqualified persons after May 26, 1969; (2) the lapse of the 5-year period (or longer period approved
by the Commissioner under section 4943(c)(7)) to dispose of holdings acquired by gift or bequest; or (3)
the lapse of the 10-, 15-, or 20-year first phase holding period? (Use Schedule C, Form 4720, to determine
if the foundation had excess business holdings in 2024.) .....................
3b
 
 
4a
Did the foundation invest during the year any amount in a manner that would jeopardize its charitable purposes?
4a
 
No
b
Did the foundation make any investment in a prior year (but after December 31, 1969) that could jeopardize its
charitable purpose that had not been removed from jeopardy before the first day of the tax year beginning in 2024? ..
4b
 
No
Form 990-PF (2024)
Form 990-PF (2024)
Page 6
Part VI-B
Statements Regarding Activities for Which Form 4720 May Be Required (continued)
5a
During the year did the foundation pay or incur any amount to:
Yes
No
(1) Carry on propaganda, or otherwise attempt to influence legislation (section 4945(e))? ..........
5a(1)
 
No
(2) Influence the outcome of any specific public election (see section 4955); or to carry
on, directly or indirectly, any voter registration drive? ....................
5a(2)
 
No
(3) Provide a grant to an individual for travel, study, or other similar purposes? .............
5a(3)
 
No
(4) Provide a grant to an organization other than a charitable, etc., organization described
in section 4945(d)(4)(A)? See instructions ........................
5a(4)
 
No
(5) Provide for any purpose other than religious, charitable, scientific, literary, or
educational purposes, or for the prevention of cruelty to children or animals? .............
5a(5)
 
No
b
If any answer is "Yes" to 5a(1)–(5), did any of the transactions fail to qualify under the exceptions described in
Regulations section 53.4945 or in a current notice regarding disaster assistance? See instructions ........
5b
 
 
c
Organizations relying on a current notice regarding disaster assistance check .........right arrow
d
If the answer is "Yes" to question 5a(4), does the foundation claim exemption from the
tax because it maintained expenditure responsibility for the grant? .................
5d
 
 
If "Yes," attach the statement required by Regulations section 53.4945–5(d).
6a
Did the foundation, during the year, receive any funds, directly or indirectly, to pay premiums on
a personal benefit contract? .............................
6a
 
No
b
Did the foundation, during the year, pay premiums, directly or indirectly, on a personal benefit contract? ....
6b
 
No
If "Yes" to 6b, file Form 8870.
7a
At any time during the tax year, was the foundation a party to a prohibited tax shelter transaction?
7a
 
No
b
If "Yes", did the foundation receive any proceeds or have any net income attributable to the transaction? .....
7b
 
 
8
Is the foundation subject to the section 4960 tax on payment(s) of more than $1,000,000 in remuneration or
excess parachute payment during the year? .........................
8
 
No
Part VII
Information About Officers, Directors, Trustees, Foundation Managers, Highly Paid Employees,
and Contractors
1 List all officers, directors, trustees, foundation managers and their compensation. See instructions
(a) Name and address (b) Title, and average
hours per week
devoted to position 		(c) Compensation
 (If not paid, enter
-0-) 		(d) Contributions to employee benefit plans and deferred compensation (e) Expense account,
other allowances
Brinkley Thorne President
1.00 		0 0 0
356 Worth Avenue Apt B-2
Palm Beach,FL33480
Mazie L Cox Vice President
1.00 		0 0 0
356 Worth Avenue Apt B-2
Palm Beach,FL33480
Yarrow Thorne Secretary
1.00 		0 0 0
1219 N Main Road
Jamestowm,RI028352217
Dune Thorne Treasurer
1.00 		0 0 0
C/O Brown Advisory 100 High St 27th
Floor
Boston,MA02110
2 Compensation of five highest-paid employees (other than those included on line 1—see instructions). If none, enter “NONE."
(a) Name and address of each employee paid more than $50,000 (b) Title, and average
hours per week
devoted to position 		(c) Compensation (d) Contributions to
employee benefit
plans and deferred
compensation 		(e) Expense account,
other allowances
NONE
Total number of other employees paid over $50,000...................right arrow 0
Form 990-PF (2024)
Form 990-PF (2024)
Page 7
Part VII
Information About Officers, Directors, Trustees, Foundation Managers, Highly Paid Employees,
and Contractors (continued)
3 Five highest-paid independent contractors for professional services (see instructions). If none, enter "NONE".
(a) Name and address of each person paid more than $50,000 (b) Type of service (c) Compensation
NONE
Total number of others receiving over $50,000 for professional services.............right arrow0
Part VIII-A
Summary of Direct Charitable Activities
List the foundation’s four largest direct charitable activities during the tax year. Include relevant statistical information such as the number of organizations and other beneficiaries served, conferences convened, research papers produced, etc. Expenses
1  
2  
3  
4  
Part VIII-B
Summary of Program-Related Investments (see instructions)
Describe the two largest program-related investments made by the foundation during the tax year on lines 1 and 2. Amount
1  
2  
All other program-related investments. See instructions.
3  
Total. Add lines 1 through 3.........................right arrow0
Form 990-PF (2024)
Form 990-PF (2024)
Page 8
Part IX
Minimum Investment Return (All domestic foundations must complete this part. Foreign foundations, see instructions.)
1
Fair market value of assets not used (or held for use) directly in carrying out charitable, etc.,
purposes:
a
Average monthly fair market value of securities...................
1a
644,388
b
Average of monthly cash balances.......................
1b
136,932
c
Fair market value of all other assets (see instructions)................
1c
3,648,575
d
Total (add lines 1a, b, and c).........................
1d
4,429,895
e
Reduction claimed for blockage or other factors reported on lines 1a and
1c (attach detailed explanation) .............
1e
0
2
Acquisition indebtedness applicable to line 1 assets..................
2
0
3
Subtract line 2 from line 1d.........................
3
4,429,895
4
Cash deemed held for charitable activities. Enter 1.5% (0.015) of line 3 (for greater amount, see
instructions) .............................
4
66,448
5
Net value of noncharitable-use assets. Subtract line 4 from line 3. ............
5
4,363,447
6
Minimum investment return. Enter 5% (0.05) of line 5................
6
218,172
Part X
Distributable Amount (see instructions) (Section 4942(j)(3) and (j)(5) private operating foundations and certain foreign organizations check here right arrow and do not complete this part.)
1
Minimum investment return from Part IX, line 6..................
1
218,172
2a
Tax on investment income for 2024 from Part V, line 5 .......
2a
12,077
b
Income tax for 2024. (This does not include the tax from Part V.) ...
2b
 
c
Add lines 2a and 2b............................
2c
12,077
3
Distributable amount before adjustments. Subtract line 2c from line 1............
3
206,095
4
Recoveries of amounts treated as qualifying distributions................
4
89,200
5
Add lines 3 and 4............................
5
295,295
6
Deduction from distributable amount (see instructions).................
6
0
7
Distributable amount as adjusted. Subtract line 6 from line 5. Enter here and on Part XII, line 1 ...
7
295,295
Part XI
Qualifying Distributions (see instructions)
1
Amounts paid (including administrative expenses) to accomplish charitable, etc., purposes:
a
Expenses, contributions, gifts, etc.—total from Part I, column (d), line 26 ..........
1a
572,414
b
Program-related investments—total from Part VIII-B..................
1b
0
2
Amounts paid to acquire assets used (or held for use) directly in carrying out charitable, etc.,
purposes...............................
2
 
3
Amounts set aside for specific charitable projects that satisfy the:
a
Suitability test (prior IRS approval required)....................
3a
 
b
Cash distribution test (attach the required schedule) .................
3b
 
4
Qualifying distributions. Add lines 1a through 3b. Enter here and on Part XII, line 4. .......
4
572,414
Form 990-PF (2024)
Form 990-PF (2024)
Page 9
Part XII
Undistributed Income (see instructions)
(a)
Corpus 		(b)
Years prior to 2023 		(c)
2023 		(d)
2024
1 Distributable amount for 2024 from Part X, line 7 295,295
2 Undistributed income, if any, as of the end of 2024:
a Enter amount for 2023 only....... 0
b Total for prior years:20 , 20, 20 0
3 Excess distributions carryover, if any, to 2024:
a From 2019...... 116,761
b From 2020...... 286,005
c From 2021...... 109,261
d From 2022...... 751,345
e From 2023...... 493,959
f Total of lines 3a through e ........ 1,757,331
4Qualifying distributions for 2024 from Part
XI, line 4: right arrow$ 572,414
a Applied to 2023, but not more than line 2a 0
b Applied to undistributed income of prior years
(Election required—see instructions)..... 		0
c Treated as distributions out of corpus (Election
required—see instructions)........ 		0
d Applied to 2024 distributable amount..... 295,295
e Remaining amount distributed out of corpus 277,119
5 Excess distributions carryover applied to 2024. 0 0
(If an amount appears in column (d), the
same amount must be shown in column (a).)
6Enter the net total of each column as
indicated below:
a Corpus. Add lines 3f, 4c, and 4e. Subtract line 5 2,034,450
b Prior years’ undistributed income. Subtract
line 4b from line 2b .......... 		0
c Enter the amount of prior years’ undistributed
income for which a notice of deficiency has
been issued, or on which the section 4942(a)
tax has been previously assessed...... 		0
d Subtract line 6c from line 6b. Taxable amount
—see instructions ........... 		0
e Undistributed income for 2023. Subtract line
4a from line 2a. Taxable amount—see
instructions ............. 		0
f Undistributed income for 2024. Subtract
lines 4d and 5 from line 1. This amount must
be distributed in 2025 .......... 		0
7 Amounts treated as distributions out of
corpus to satisfy requirements imposed by
section 170(b)(1)(F) or 4942(g)(3) (Election may
be required - see instructions) ....... 		0
8 Excess distributions carryover from 2019 not
applied on line 5 or line 7 (see instructions) ... 		116,761
9 Excess distributions carryover to 2025.
Subtract lines 7 and 8 from line 6a ...... 		1,917,689
10 Analysis of line 9:
a Excess from 2020.... 286,005
b Excess from 2021.... 109,261
c Excess from 2022.... 751,345
d Excess from 2023.... 493,959
e Excess from 2024.... 277,119
Form 990-PF (2024)
Form 990-PF (2024)
Page 10
Part XIII
Private Operating Foundations (see instructions and Part VI-A, question 9)
1a If the foundation has received a ruling or determination letter that it is a private operating
foundation, and the ruling is effective for 2024, enter the date of the ruling ...... right arrow
 
b Check box to indicate whether the organization is a private operating foundation described in section or
2a Enter the lesser of the adjusted net
income from Part I or the minimum
investment return from Part IX for each
year listed .......... 		Tax year Prior 3 years (e) Total
(a) 2024 (b) 2023 (c) 2022 (d) 2021
         
b 85% (0.85) of line 2a .........          
c Qualifying distributions from Part XI,
line 4 for each year listed ..... 		         
d Amounts included in line 2c not used directly
for active conduct of exempt activities .......... 		         
e Qualifying distributions made directly
for active conduct of exempt activities.
Subtract line 2d from line 2c .... 		         
3 Complete 3a, b, or c for the
alternative test relied upon:
a “Assets" alternative test—enter:
(1) Value of all assets ......          
(2) Value of assets qualifying
under section 4942(j)(3)(B)(i)		          
b “Endowment" alternative test— enter 2/3
of minimum investment return shown in
Part IX, line 6 for each year listed .. 		         
c “Support" alternative test—enter:
(1) Total support other than gross
investment income (interest,
dividends, rents, payments
on securities loans (section
512(a)(5)), or royalties) .... 		         
(2) Support from general public
and 5 or more exempt
organizations as provided in
section 4942(j)(3)(B)(iii).... 		         
(3) Largest amount of support
from an exempt organization		          
(4) Gross investment income          
Part XIV
Supplementary Information (Complete this part only if the foundation had $5,000 or more in
assets at any time during the year—see instructions.)
1Information Regarding Foundation Managers:
aList any managers of the foundation who have contributed more than 2% of the total contributions received by the foundation
before the close of any tax year (but only if they have contributed more than $5,000). (See section 507(d)(2).)
Brinkley Thorne
bList any managers of the foundation who own 10% or more of the stock of a corporation (or an equally large portion of the
ownership of a partnership or other entity) of which the foundation has a 10% or greater interest.
2Information Regarding Contribution, Grant, Gift, Loan, Scholarship, etc., Programs:
Check here right arrow if the foundation only makes contributions to preselected charitable organizations and does not accept
unsolicited requests for funds. If the foundation makes gifts, grants, etc. to individuals or organizations under
other conditions, complete items 2a, b, c, and d. See instructions
aThe name, address, and telephone number or e-mail address of the person to whom applications should be addressed:
Dune Thorne
100 High Street 27th Floor
Boston,MA02110
(617) 717-6373
dthorne@brownadvisory.com
bThe form in which applications should be submitted and information and materials they should include:
Letter that includes the purpose of the grant requested and Internal Revenue Service exemption.
cAny submission deadlines:
N/A
dAny restrictions or limitations on awards, such as by geographical areas, charitable fields, kinds of institutions, or other
factors:
Awards are available only to public charities that qualify under under Section 501(c)(3).
Form 990-PF (2024)
Form 990-PF (2024)
Page 11
Part XIV
Supplementary Information (continued)
3 Grants and Contributions Paid During the Year or Approved for Future Payment
Recipient If recipient is an individual,
show any relationship to
any foundation manager
or substantial contributor
 Foundation
status of
recipient 		Purpose of grant or
contribution 		Amount
Name and address (home or business)
aPaid during the year

Aspen Public Radio

110 E Hallam 134
Aspen,CO81611 		  PC Operations budget assistance 1,000

Avenue Concept Inc

304 Lockwood Street
Providence,RI02907 		  PC Operations budget assistance 195,000

Bay Chamber Concerts Inc

PO Box 599
Rockport,ME04856 		  PC Operations budget assistance 100,000

Boston Impact Initiative

PO Box 300443
Jamaica Plain,MA02130 		  PC Operations budget assistance 25,000

Trustees of Dartmouth College

7 Lebanon Street Suite 302 6015
Hanover,NH03755 		  PC Operations budget assistance 50,000

The William A Farnsworth Library and Art Museum Inc

356 Main Street
Rockland,ME04841 		  PC Operations budget assistance 6,624

Imagine North Carolina First

PO Box 428
Raleigh,NC27602 		  PC Operations budget assistance 5,000

Knox County Homeless Coalition

PO Box 1696
Rockland,ME04841 		  PC Operations budget assistance 5,000

Lifeflight Foundation

PO Box 899 13 Main Street 2nd Floor
Camden,ME04843 		  PC Operations budget assistance 5,000

Living Observatory Inc

139 Bartlett Road
Plymouth,MA02360 		  PC Operations budget assistance 1,000

Maine Public Broadcasting Corp

1450 Lisbon Street
Lewiston,ME04240 		  PC Operations budget assistance 10,000

Middlesex School

1400 Lowell Rd
Concord,MA017425210 		  PC Operations budget assistance 50,000

Milton Academy

170 Centre St
Milton,MA02186 		  PC Operations budget assistance 25,000

Presidents and Fellows of Harvard

1033 Massachusetts Ave 3rd Floor
Cambridge,MA02138 		  PC Operations budget assistance 10,000

Rockport Library Foundation

PO Box 204
Rockport,ME04856 		  PC Operations budget assistance 1,325

Rocky Mountain Public Media Inc

2101 Arapahoe Street
Denver,CO80205 		  PC Operations budget assistance 1,000

National Debutante Cotillion Foundation Inc

2500 Q Street NW 720
Washington,DC45429 		  PC Operations budget assistance 31,200

United States Ski and Snowboard Association

177 Huntington Ave
Boston,MA021153153 		  PC Operations budget assistance 45,000

YMCA of the USA

101 N Wacker Drive
Chicago,IL60606 		  PC Operations budget assistance 5,000
Total .................................right arrow 3a 572,149
bApproved for future payment
Total ................................. right arrow 3b 0
Form 990-PF (2024)
Form 990-PF (2024)
Page 12
Part XV-A
Analysis of Income-Producing Activities
Enter gross amounts unless otherwise indicated. Unrelated business income Excluded by section 512, 513, or 514 (e)
Related or exempt
function income
(See instructions.)
1Program service revenue: (a)
Business code 		(b)
Amount 		(c)
Exclusion code 		(d)
Amount
a
b
c
d
e
f
gFees and contracts from government agencies          
2 Membership dues and assessments ....          
3 Interest on savings and temporary cash
investments ........... 		         
4 Dividends and interest from securities .... 900099 97 14 69,092  
5 Net rental income or (loss) from real estate:
aDebt-financed property......          
bNot debt-financed property.....          
6 Net rental income or (loss) from personal property          
7 Other investment income ..... 900099 36 14 32,420  
8 Gain or (loss) from sales of assets other than
inventory ............ 		900099 180 18 381,330  
9 Net income or (loss) from special events:          
10 Gross profit or (loss) from sales of inventory          
11 Other revenue:
aMorris Foundation, LLC K-1 Ordinary Income - UBI 		900099 609      
bMorris Foundation, LLC K-1 Rental     14 -159  
cReturned Grant         89,200
dMorris Foundation, LLC K-1 Rental - UBI 900099 -151     0
e
12 Subtotal. Add columns (b), (d), and (e) .. 771 482,683 89,200
13Total. Add line 12, columns (b), (d), and (e)..................
13
572,654
(See worksheet in line 13 instructions to verify calculations.)
Part XV-B
Relationship of Activities to the Accomplishment of Exempt Purposes
Line No.
DownArrow 		Explain below how each activity for which income is reported in column (e) of Part XV-A contributed importantly to
the accomplishment of the foundation’s exempt purposes (other than by providing funds for such purposes). (See
instructions.)
3 The $89,200 reported on column E represents returned grants
Form 990-PF (2024)
Form 990-PF (2024)
Page 13
Part XVI
Information Regarding Transfers To and Transactions and Relationships With Noncharitable Exempt Organizations
1
Did the organization directly or indirectly engage in any of the following with any other organization described in section 501(c) (other than section 501(c)(3) organizations) or in section 527, relating to political organizations?
Yes
No
a
Transfers from the reporting foundation to a noncharitable exempt organization of:
(1) Cash...................................
1a(1)
 
No
(2) Other assets.................................
1a(2)
 
No
b
Other transactions:
(1) Sales of assets to a noncharitable exempt organization....................
1b(1)
 
No
(2) Purchases of assets from a noncharitable exempt organization..................
1b(2)
 
No
(3) Rental of facilities, equipment, or other assets.......................
1b(3)
 
No
(4) Reimbursement arrangements...........................
1b(4)
 
No
(5) Loans or loan guarantees.............................
1b(5)
 
No
(6) Performance of services or membership or fundraising solicitations................
1b(6)
 
No
c
Sharing of facilities, equipment, mailing lists, other assets, or paid employees..............
1c
 
No
d
If the answer to any of the above is "Yes," complete the following schedule. Column (b) should always show the fair market value
of the goods, other assets, or services given by the reporting foundation. If the foundation received less than fair market value
in any transaction or sharing arrangement, show in column (d) the value of the goods, other assets, or services received.
(a) Line No. (b) Amount involved (c) Name of noncharitable exempt organization (d) Description of transfers, transactions, and sharing arrangements
2a
Is the foundation directly or indirectly affiliated with, or related to, one or more tax-exempt organizations
described in section 501(c) (other than section 501(c)(3)) or in section 527? ...........
b
If "Yes," complete the following schedule.

(a) Name of organization (b) Type of organization (c) Description of relationship
Sign Here
Under penalties of perjury, I declare that I have examined this return, including accompanying schedules and statements, and to the best of my knowledge and belief, it is true, correct, and complete. Declaration of preparer (other than taxpayer) is based on all information of which preparer has any knowledge.
right arrow right arrow
May the IRS discuss this return
with the preparer shown below?
See instructions.
Signature of officer or trustee Date Title
Paid Preparer Use Only Print/Type preparer's name Preparer's Signature Date Check if self-
employed right arrow		 PTIN
Firm's name Right Arrow
 Firm's EIN Right Arrow
Firm's address Right Arrow


 Phone no.
Form 990-PF (2024)
Additional Data


Software ID:  
Software Version:  


Form 990PF - Special Condition Description:
Special Condition Description

TY 2024 AccountingFeesSchedule
Name:
The Thorne Cox Family Foundation
 
C/O Brown Advisory
EIN:
46-4274950
Category Amount Net Investment Income Adjusted Net Income Disbursements for Charitable Purposes
Accounting Fees 11,000 11,000   0

TY 2024 InvestmentsOtherSchedule2
Name:
The Thorne Cox Family Foundation
 
C/O Brown Advisory
EIN:
46-4274950
Category/ Item Listed at Cost or FMV Book Value End of Year Fair Market Value
Investment in the Morris Foundation FMV 3,623,575 3,623,575
Brown Advisory Sustainable BD Instl FMV 185,794 185,794
Brown Advisory Sustain Growth Inst FMV 110,913 110,913
Brown Advisory Sustn Sm Cap Core I FMV 73,493 73,493
Brown Advisory Sustain Value FD I FMV 108,059 108,059

TY 2024 OtherAssetsSchedule
Name:
The Thorne Cox Family Foundation
 
C/O Brown Advisory
EIN:
46-4274950
Description Beginning of Year - Book Value End of Year - Book Value End of Year - Fair Market Value
SAFE Note 0 25,000 25,000


TY 2024 OtherDecreasesSchedule
Name:
The Thorne Cox Family Foundation
 
C/O Brown Advisory
EIN:
46-4274950
Description Amount
Unrealized Loss 82


TY 2024 OtherExpensesSchedule
Name:
The Thorne Cox Family Foundation
 
C/O Brown Advisory
EIN:
46-4274950
Description Revenue and Expenses per Books Net Investment Income Adjusted Net Income Disbursements for Charitable Purposes
Morris Foundation, LLC K-1 Other Deductions 377 377   0
Morris Foundation, LLC K-1 Portolio Deductions 2% Floor 41,278 40,789   0
Morris Foundation, LLC K-1 Charitable Contributions 3 0   3
Morris Foundation, LLC K-1 Non-Deductible Expenses 68 0   68
Morris Foundation, LLC K-1 Royalty Deduction 14,041 14,041   0
Filing Fees 194 0   194


TY 2024 OtherIncomeSchedule2
Name:
The Thorne Cox Family Foundation
 
C/O Brown Advisory
EIN:
46-4274950
Description Revenue And Expenses Per Books Net Investment Income Adjusted Net Income
Morris Foundation, LLC K-1 Ordinary Income -217 -217 -217
Morris Foundation, LLC K-1 Other Income/Loss 15,328 15,328 15,328
Morris Foundation, LLC K-1 Other Income/Loss - UBI 36 0 36
Morris Foundation, LLC K-1 Royalties 17,309 17,309 17,309
Morris Foundation, LLC K-1 Ordinary Income - UBI 609   609
Morris Foundation, LLC K-1 Rental -159 -159 -159
Returned Grant 89,200   89,200
Morris Foundation, LLC K-1 Rental - UBI -151   -151


TY 2024 OtherIncreasesSchedule
Name:
The Thorne Cox Family Foundation
 
C/O Brown Advisory
EIN:
46-4274950
Description Amount
Morris Foundation, LLC K-1 Cumulative tax basis adjustment 383,678


TY 2024 OtherProfessionalFeesSchedule
Name:
The Thorne Cox Family Foundation
 
C/O Brown Advisory
EIN:
46-4274950
Category Amount Net Investment Income Adjusted Net Income Disbursements for Charitable Purposes
Investment Management Fees 1,799 1,799   0


TY 2024 TaxesSchedule
Name:
The Thorne Cox Family Foundation
 
C/O Brown Advisory
EIN:
46-4274950
Category Amount Net Investment Income Adjusted Net Income Disbursements for Charitable Purposes
Morris Foundation, LLC K-1 Foreign Taxes 1,268 1,267   0
Federal Taxes 11,000 0   0
State Taxes 7 0   0