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Nonprofit · EIN 46-1637111

MAINFRAME STUDIOS

Tax-exempt · DES MOINES, IA 50309

Financials

$1.5M$2M2023$1.7M$2M2024$1.8M$2.1M2025
Revenue Expenses · by fiscal year end
Financials of MAINFRAME STUDIOS by year, from its e-filed returns
Year endedFormRevenueExpensesNet incomeTotal assetsLiabilitiesNet assets
December 31, 2025990$1,762,839$2,052,863-$290,024$9,422,363$150,258$9,272,105
December 31, 2024990$1,662,532$1,982,601-$320,069$9,808,236$254,900$9,553,336
December 31, 2023990$1,527,994$2,009,905-$481,911$10,125,236$251,831$9,873,405
Financial details: 990 for the year ended December 31, 2025

Revenue

Contributions, gifts and grants
$335,908
Program service revenue
$1,394,671
Investment income
$21,405
Other revenue
$10,855

Expenses

Grants and similar amounts paid
$0
Other salaries and wages
$253,532
Salaries, compensation and benefits (total)
$295,390
Professional fundraising fees
$0
Occupancy
$541,593
Travel
$4,029
Depreciation
$779,466
Program services (functional)
$1,686,544
Management and general (functional)
$323,518
Fundraising (functional)
$42,801

Balance sheet and other

Total assets, start of year
$9,808,236
Total assets, end of year
$9,422,363
Total liabilities, end of year
$150,258
Net assets, end of year
$9,272,105
Land, buildings and equipment
$8,215,211
Gross receipts
$1,762,839
Employees
6
Volunteers
17
Year formed
2012
State of legal domicile
IA

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 for the year ended December 31, 2025, highest compensation first.

NameTitleHours / weekCompensation
Julia Franklin-JonesExecutive Director
Key employee
50$114,854
Jill WellsSecretary
Trustee or director, Officer
0.5$3,200
John McGowanPresident
Trustee or director, Officer
10$0
Sarah YoungVice President
Trustee or director, Officer
1$0
Michael TrettinTreasurer
Trustee or director, Officer
3$0
Justin MandelbaumDirector
Trustee or director
0.25$0
David SchmitzDirector
Trustee or director
0.25$0
Meredith Hubbell StahlDirector
Trustee or director
0.25$0
Dr Kelly BaumDirector
Trustee or director
0.25$0
Gretchen BohlingDirector
Trustee or director
0.25$0
Jeff ChelesvigDirector0.25$0
990 for the year ended December 31, 2024: 11 people
NameTitleHours / weekCompensation
John McGowanPresident
Trustee or director, Officer
10$0
Sarah YoungVice President
Trustee or director, Officer
1$0
Michael TrettinTreasurer
Trustee or director, Officer
3$0
Jill WellsSecretary
Trustee or director, Officer
0.5$0
Justin MandelbaumDirector
Trustee or director
0.25$0
David SchmitzDirector
Trustee or director
0.25$0
Meredith Hubbell StahlDirector
Trustee or director
0.25$0
Dr Kelly BaumDirector
Trustee or director
0.25$0
Gretchen BohlingDirector
Trustee or director
0.25$0
Jeff ChelesvigDirector0.25$0
Julia Franklin-JonesExecutive Director
Key employee
50$0
990 for the year ended December 31, 2023: 9 people
NameTitleHours / weekCompensation
Justin MandelbaumPresident
Trustee or director, Officer
10$0
John McGowanVice President
Trustee or director, Officer
2$0
Michael TrettinTreasurer
Trustee or director, Officer
2$0
Gretchen BohlingSecretary
Trustee or director, Officer
0.25$0
John MandelbaumMember
Trustee or director
0.25$0
David SchmitzMember
Trustee or director
0.25$0
Meredith StahlMember
Trustee or director
0.25$0
Jill WellsMember
Trustee or director
0.25$0
Sarah YoungMember
Trustee or director
0.25$0

Address and contacts

Address (IRS master file)
900 KEOSAUQUA WAY, DES MOINES, IA 50309-1501
In care of
% JUSTIN MANDELBAUM
Mailing address (990-N for 2013)
4500 Westown Parkway Suite 115, West Des Moines IA 50266
Principal officer (990 for 2025)
JOHN MCGOWAN, 900 KEOSAUQUA WAY 100, DES MOINES, IA 50309
Principal officer (990-N for 2013)
Justin Mandelbaum, 4500 Westown Parkway Suite 115, West Des Moines IA 50266
Signed the 990
MICHAEL TRETTIN, TREASURER
Phone
(515) 216-4253
Return prepared by
THE PLANNERS TAX & ACCOUNTING

Mission

Mainframe Studios provides affordable arts workspace and fosters creative communities in central Iowa.

990 for the year ended December 31, 2025

Program accomplishments

  • In 2025, Mainframe underwent strategic planning and revised our mission and vision statements and added organizational values of respect, collaboration, accessibility, financial sustainability, and risk-taking. Mainframe identified four strategic pillars to guide our work over the next three years: financial health, internal strength, mission delivery, and organization awareness. Mainframe studios completed its third full year operating at 98% capacity. 181 creative workspaces are used by over 220 artists and 8 arts related nonprofits. Mainframe maintained a waitlist of over 155 applicants in 2025. Income from affordable rents generated enough revenue to cover operating costs. An additional 4650 square foot event rental space, The Big Room, provides a place for weddings, converences, workshops, corporate parties and fundraisers for a rental fee. We receive a portion of food and beverage sales that take place in this space. The Big Room also serves as s classroom for our 12-week session of artist professional development and quarterly tenant meetings. Our second-floor common area serves as a learning space where artists regularly share skills with each other. Studio 108 is a flexible arts and culture education space that is used for K-12 art field trips during the day and rented to dance groups on the evenings and weekends to generate additional rental income and address community needs.
    Expenses $1,655,333 · revenue $1,405,525
  • Mainframe Studios spends a portion of of its budget on programming for monthly First Friday Open Studio events that attract thousands of visitors. We average 2,464 attendees each First Friday with over 14,250 people attending each month. That accounts for a sizable community impact and a total of 174,238 visitor experiences each year. The festive, free First Friday Studio events feature unique and creative experiences for audiences each month. These include exhibitions in 4 gallery spaces, arts activities, and live music entertainment relating to themed events and various art forms such as ceramics, fashion, printmaking and painting. First Fridays also feature local musicians and affordable dinner options by local food vendors and resident caterers, Tangerine Food Company. Tenant/Artists open their studios to connect with new customers and community members to help further their careers and artistic practices. Artists/tenants are paid to support First Friday events by documenting the events and designing all printed and social media. Tenants/Teaching artists support our K-12 art field experiences that saw 998 youth participate in 2025. In fall 2025, Mainframe launched Work of Art: Business Skills for Artists, a 12 week program for a 25-person cohort to help artists grow their skills and advance their careers. Mainframe also self publishes an annual gift guide that showcases creative works for sale and includes stories about our artists and partners.
    Expenses $31,211

What it must file and when

IRS records say it files Form 990 or 990-EZ. Based on its last return; a smaller organization may file the 990-N. 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 on file
2024December 31, 2024May 15, 2025990 on file
2023December 31, 2023May 15, 2024990 on file

IRS record

EIN
46-1637111
Tax-exempt status
501(c)(3): Charitable, religious, educational or scientific organization
Foundation status
Publicly supported organization (509(a)(2))
Donations deductible (Pub 78)
Public charity, 50% deduction limit
Exempt since
2014
Accounting year ends
December
Files
Form 990 or 990-EZ
Assets (IRS master file)
$9,422,363
Income (IRS master file)
$1,762,839

Filing history

FormYear endedRevenueExpensesAssetsReturn
990December 2025$1,762,839$2,052,863$9,422,363XML
990December 2024$1,662,532$1,982,601$9,808,236IRS
990December 2023$1,527,994$2,009,905$10,125,236XML
990December 2022$3,251,639$1,559,009$10,836,605IRS
990December 2021–––IRS
990December 2020–––IRS
990-N for 2013
Officer: Justin Mandelbaum
December 31, 2013≤ $50,000 receipts––e-Postcard

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 46-1637111).

Questions about MAINFRAME STUDIOS

What is the EIN of MAINFRAME STUDIOS?
The employer identification number (EIN) of MAINFRAME STUDIOS is 46-1637111.
Is MAINFRAME STUDIOS tax-exempt?
Yes. The IRS lists it as tax-exempt under section 501(c)(3) since 2014.
Are donations to MAINFRAME STUDIOS tax-deductible?
Yes. It is listed in IRS Publication 78 (Public charity, 50% deduction limit).
Which annual return does MAINFRAME STUDIOS file?
Form 990 or 990-EZ. Based on its last return; a smaller organization may file the 990-N.
When is the next return of MAINFRAME STUDIOS 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 MAINFRAME STUDIOS last file with the IRS?
The latest return in the IRS public files is the 990 for the year ended December 2025.
Who is the principal officer of MAINFRAME STUDIOS?
The 990 for the year ended December 31, 2025 names JOHN MCGOWAN.
Who are the officers and directors of MAINFRAME STUDIOS?
The 990 for the year ended December 31, 2025 lists 11 people; 2 received compensation from the organization, the highest $114,854 (Julia Franklin-Jones, Executive Director).
How much revenue does MAINFRAME STUDIOS have?
On its 990 for the year ended December 31, 2025 it reported revenue of $1,762,839, expenses of $2,052,863 and total assets of $9,422,363 at year end.

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