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IRS-authorized e-file provider · not the IRS

Nonprofit · EIN 86-2621132

COMBINATORICS CONSORTIUM INC

Also known as COMBINATORICS CONSORTIUM

Tax-exempt · MINNEAPOLIS, MN 55419

Financials

$41K$33K2023$32K$57K2024$30K$41K2025
Revenue Expenses · by fiscal year end
Financials of COMBINATORICS CONSORTIUM INC by year, from its e-filed returns
Year endedFormRevenueExpensesNet incomeTotal assetsLiabilitiesNet assets
December 31, 2025990-EZ$29,679$41,443-$11,764$152,157$0$152,157
December 31, 2024990-EZ$32,478$57,092-$24,614$163,921$0$163,921
December 31, 2023990-EZ$40,914$33,290$7,624$188,535$0$188,535
Financial details: 990-EZ for the year ended December 31, 2025

Revenue

Contributions, gifts and grants
$29,629
Program service revenue
$50
Investment income
$0
Other revenue
$0

Expenses

Grants and similar amounts paid
$7,654
Compensation of officers, directors and key employees
$0
Salaries, compensation and benefits (total)
$0
Professional fees and payments to contractors
$29,800
Other expenses
$3,989
Program services (functional)
$2,750

Balance sheet and other

Total assets, start of year
$163,921
Total assets, end of year
$152,157
Total liabilities, end of year
$0
Net assets, end of year
$152,157
Cash, savings and investments
$152,157
Gross receipts
$29,679

From the e-filed returns the IRS publishes as XML (latest three processing years; amended returns replace the original). PDF copies at the IRS.

Officers, directors and key employees

As listed on the 990-EZ for the year ended December 31, 2025, highest compensation first.

NameTitleHours / weekCompensation
Victor ReinerTreasurer5$0
Sara BilleyPresident5$0
Volkmar WelkerVice President5$0
Michael ZabrockiSecretary5$0
990-EZ for the year ended December 31, 2024: 4 people
NameTitleHours / weekCompensation
Victor ReinerTreasurer1$0
Sara BilleyPresident1$0
Volkmar WelkerVice President1$0
Michael ZabrockiSecretary1$0
990-EZ for the year ended December 31, 2023: 4 people
NameTitleHours / weekCompensation
Victor ReinerTreasurer1$0
Sara BilleyPresident1$0
Volkmar WelkerVice President1$0
Michael ZabrockiSecretary1$0

Address and contacts

Address (IRS master file)
5007 DUPONT AVE S, MINNEAPOLIS, MN 55419-1149
In care of
% VICTOR REINER
Signed the 990-EZ
Michael Zabrocki, Secretary
Phone
(612) 625-6682

Mission

publishing, supporting conferences, support research

990-EZ for the year ended December 31, 2025

Program accomplishments

  • Combinatorial Theory - journal - payments to 4 independent contractors; payments of software to run journal
    Expenses $2,750 · grants $12,250
  • Algebraic Combinatorics - journal - payments to 7 independent contractors for running journal
    grants $17,549
  • Conference support - grants to conferences GSCC 25, BadMath 2025, CAAC 2025, alternating sign matrices, 31st British Combinatorial Conference, CAAC 2026, FPSAC 2025,
    grants $7,654

What it must file and when

IRS records say it files Form 990-N (e-Postcard). Gross receipts normally $50,000 or less. Its accounting year ends in December, so each return is due on the 15th day of the 5th month after that.

Tax yearYear endedDueIRS public records
2025December 31, 2025May 15, 2026990-EZ on file
2024December 31, 2024May 15, 2025990-EZ on file
2023December 31, 2023May 15, 2024990-EZ on file

File the 2026 990-N for COMBINATORICS CONSORTIUM INC

Due May 17, 2027 · e-filed with the IRS by 990.tax, an IRS-authorized e-file provider

IRS record

EIN
86-2621132
Tax-exempt status
501(c)(3): Charitable, religious, educational or scientific organization
Foundation status
Publicly supported organization (170(b)(1)(A)(vi))
Donations deductible (Pub 78)
Public charity, 50% deduction limit
Exempt since
2021
Accounting year ends
December
Files
Form 990-N (e-Postcard)
Assets (IRS master file)
$152,157
Income (IRS master file)
$29,679

Filing history

FormYear endedRevenueExpensesAssetsReturn
990-EZDecember 2025$29,679$41,443$152,157IRS
990-EZDecember 2024$32,478$57,092$163,921IRS
990-EZDecember 2023$40,914$33,290$188,535XML
990-EZDecember 2022–––IRS
990-EZDecember 2021–––IRS

990-N: the IRS bulk file holds only the latest e-Postcard per organization; earlier years come from archived copies of that file since 2020 and can have gaps (the IRS e-Postcard search lists every one). 990, 990-EZ, 990-PF, 990-T: every e-filed return in the IRS e-file index since 2019; XML for the latest three processing years, amounts from the IRS Statistics of Income extracts before that. PDF copies and determination letters at the IRS (search EIN 86-2621132).

Questions about COMBINATORICS CONSORTIUM INC

What is the EIN of COMBINATORICS CONSORTIUM INC?
The employer identification number (EIN) of COMBINATORICS CONSORTIUM INC is 86-2621132.
Is COMBINATORICS CONSORTIUM INC tax-exempt?
Yes. The IRS lists it as tax-exempt under section 501(c)(3) since 2021.
Are donations to COMBINATORICS CONSORTIUM INC tax-deductible?
Yes. It is listed in IRS Publication 78 (Public charity, 50% deduction limit).
Which annual return does COMBINATORICS CONSORTIUM INC file?
Form 990-N (e-Postcard). Gross receipts normally $50,000 or less.
When is the next return of COMBINATORICS CONSORTIUM INC due?
The return for tax year 2026 (the year ending December 31, 2026) is due May 17, 2027. Form 8868 extends it by six months; the 990-N cannot be extended.
When did COMBINATORICS CONSORTIUM INC last file with the IRS?
The latest return in the IRS public files is the 990-EZ for the year ended December 2025.
Who are the officers and directors of COMBINATORICS CONSORTIUM INC?
The 990-EZ for the year ended December 31, 2025 lists 4 people; 0 received compensation from the organization.
How much revenue does COMBINATORICS CONSORTIUM INC have?
On its 990-EZ for the year ended December 31, 2025 it reported revenue of $29,679, expenses of $41,443 and total assets of $152,157 at year end.

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