Tax-exempt organization ยท Files a Form 5500
MIDCONTINENT INDEPENDENT SYSTEM OPERATOR INC
Also filed as MISO
720 CITY CENTER DR, CARMEL, IN 46032-3826
EIN
43-1827033
Tax-exempt status
501(c)(4) social welfare
IRS · 2026-09
Deductibility
Contributions are not deductible
IRS · 2026-09
IRS ruling date
2001-01
IRS · 2026-09
NTEE code
W80
IRS · 2026-09
Latest tax period on file
2024-12
IRS · 2026-09
Revenue (latest 990)
$616,078,935
IRS · 2026-09
Assets (latest 990)
$3,354,403,000
IRS · 2026-09
Benefit plan 1, 2024 filing
MISO EMPLOYEES' RETIREMENT SAVINGS PLAN
DOL · 2025-08-28
Participants (start of year)
1,384
DOL · 2025-08-28
Plan features
code 2E2F2G2J2K2S2T3D2R
DOL · 2025-08-28
Plan type
Single-employer plan
DOL · 2025-08-28
Business code (NAICS)
221100
DOL · 2025-08-28
Benefit plan 510, 2024 filing
MIDCONTINENT INDEPENDENT SYSTEMS OPERATOR, INC. EMPLOYEE BENEFIT PLAN
DOL · 2025-07-29
Participants (start of year)
1,070
DOL · 2025-07-29