Unknown & Unclassified nonprofits in Connecticut

Unknown & Unclassified nonprofits in Connecticut. Browse 7,402 public nonprofit profiles. Review organization identities, available filing years, and their complete CharitySense profiles.

Location refers to headquarters recorded in public sources, not an organization’s service area. Classification describes its reported category and does not assess its effectiveness.

Nonprofit profiles

  1. International Association of Lions Clubs

    EIN 843906680 · Headquarters: West Hartford, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  2. International Association of Lions Clubs

    EIN 844388036 · Headquarters: Cromwell, CT, US · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-N

  3. INTERNATIONAL ASSOCIATION OF LIONS CLUBS - Watertown Lions

    EIN 061156034 · Headquarters: Watertown, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-EZ

  4. International Association of Lions Clubs Putnam Lions Club Inc

    EIN 061057279 · Headquarters: PUTNAM, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  5. International Association of Machinists & Aerospace Local 1746

    EIN 060613269 · Headquarters: EAST HARTFORD, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

  6. International Association of Machinists & Aerospace Workers

    EIN 020599079 · Headquarters: New London, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  7. International Association of Machinists & Aerospace Workers

    EIN 050391448 · Headquarters: New London, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  8. International Association of Machinists & Aerospace Workers

    EIN 050479166 · Headquarters: New London, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  9. International Association of Machinists & Aerospace Workers

    EIN 060381384 · Headquarters: New London, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  10. International Association of Machinists & Aerospace Workers

    EIN 060400748 · Headquarters: East Hartford, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  11. International Association of Machinists & Aerospace Workers

    EIN 060607923 · Headquarters: Kensington, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  12. International Association of Machinists & Aerospace Workers

    EIN 060636091 · Headquarters: Kensington, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  13. International Association of Machinists & Aerospace Workers

    EIN 060666131 · Headquarters: WINDSOR LOCKS, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

  14. International Association of Machinists & Aerospace Workers

    EIN 060730587 · Headquarters: New London, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  15. International Association of Machinists & Aerospace Workers

    EIN 066069264 · Headquarters: North Haven, CT, US · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-N

  16. International Association of Machinists & Aerospace Workers

    EIN 066069650 · Headquarters: Bethel, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  17. International Association of Machinists & Aerospace Workers

    EIN 331195137 · Headquarters: Milldale, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  18. International Association of Machinists & Aerospace Workers Local 1746 Building

    EIN 060731800 · Headquarters: EAST HARTFORD, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-EZ

  19. International Association of Machinists & Aerospace Workers Local 700

    EIN 060756083 · Headquarters: HIGGANUM, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

  20. International Association of Machinists and Aerospace Workers Cscm

    EIN 060851542 · Headquarters: EAST HARTFORD, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-EZ

  21. International Association of Theatrical and Stage Employees Local 74

    EIN 066070010 · Headquarters: NEW HAVEN, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

  22. International Brotherhd - Boilrmkrs Ir Shp Bldrs Blcksmth Frgrs & Hlpr

    EIN 060727380 · Headquarters: SALEM, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  23. International Brotherhood L1040

    EIN 060669593 · Headquarters: NEWINGTON, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-EZ

  24. International Brotherhood of Boilermakers # 614

    EIN 060728257 · Headquarters: GROTON, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

  25. International Brotherhood of Electrical Workers

    EIN 066064824 · Headquarters: DANBURY, CT, US · Unknown & Unclassified · Latest available filing year: 2022 · Primary form: IRS Form 990-N

  26. International Brotherhood of Electrical Workers

    EIN 136007364 · Headquarters: Stamford, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  27. International Brotherhood of Electrical Workers - 0261 Local

    EIN 060729150 · Headquarters: GROTON, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  28. International Brotherhood of Electrical Workers - Local 1573

    EIN 133090174 · Headquarters: Darrien, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-EZ

  29. International Brotherhood of Electrical Workers Local 420

    EIN 060716467 · Headquarters: WATERBURY, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  30. International Brotherhood of Electrical Workers Local No 90

    EIN 060400792 · Headquarters: WALLINGFORD, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

  31. International Brotherhood of Electrical Workers Local Union No 457

    EIN 060892100 · Headquarters: BERLIN, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  32. International Brotherhood of Electrical Workers Local Union No35 Association Inc

    EIN 060865102 · Headquarters: HARTFORD, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

  33. International Brotherhood of Electrical Workers Union Local Union No 35

    EIN 060400787 · Headquarters: HARTFORD, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

  34. International Brotherhood of Painters & Allied Trades Local 1122

    EIN 060693728 · Headquarters: NEW LONDON, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  35. International Brotherhood of Teamsters

    EIN 061157206 · Headquarters: STRATFORD, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  36. International Brotherhood of Teamsters

    EIN 061180033 · Headquarters: WATERBURY, CT, US · Unknown & Unclassified · Latest available filing year: 2023 · Primary form: IRS Form 990-N

  37. International Brotherhood of Teamsters Local 191

    EIN 060453477 · Headquarters: BRIDGEPORT, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  38. International Brotherhood of Teamsters Local Union 443

    EIN 060400785 · Headquarters: NEW HAVEN, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  39. International Brotherhood of Teamsters Local Union 677

    EIN 060389865 · Headquarters: CHESHIRE, CT, USA · Unknown & Unclassified · Latest available filing year: 2023 · Primary form: IRS Form 990

  40. International Dyslexia Association of Connecticut Inc

    EIN 334065585 · Headquarters: Ridgefield, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  41. International Federation of Professional & Technical Engineers

    EIN 237055400 · Headquarters: Stratford, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  42. International Institute of Business Analysis Hartord Ct Chapter

    EIN 204639151 · Headquarters: West Hartford, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  43. International Maintenance Institute Inc

    EIN 066068621 · Headquarters: Wallingford, CT, US · Unknown & Unclassified · Latest available filing year: 2023 · Primary form: IRS Form 990-N

  44. International Order of the Kings Daughters and Sons Hd Un of Circles

    EIN 060647274 · Headquarters: EAST HARTFORD, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-PF

  45. International Order of the Rainbow Girls

    EIN 061541020 · Headquarters: Hamden, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  46. International Order of the Rainbow Girls

    EIN 066049093 · Headquarters: Hamden, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  47. International Order of the Rainbow Girls

    EIN 066056702 · Headquarters: Hamden, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  48. International Order of the Rainbow Girls

    EIN 237141150 · Headquarters: Hamden, CT, US · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-N

  49. International Order of the Rainbow Girls

    EIN 237141156 · Headquarters: Hamden, CT, US · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-N

  50. International Order of the Rainbow Girls

    EIN 237141191 · Headquarters: Hamden, CT, US · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-N

  51. International Order of the Rainbow Girls

    EIN 237141192 · Headquarters: Hamden, CT, US · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-N

  52. International Order of the Rainbow Girls

    EIN 237143852 · Headquarters: Hamden, CT, US · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-N

  53. International Order of the Rainbow Girls

    EIN 237144886 · Headquarters: Hamden, CT, US · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-N

  54. International Order of the Rainbow Girls

    EIN 237144890 · Headquarters: Hamden, CT, US · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-N

  55. International Order of the Rainbow Girls

    EIN 352243494 · Headquarters: Hamden, CT, US · Unknown & Unclassified · Latest available filing year: 2021 · Primary form: IRS Form 990-N

  56. International Plant Propagators Society

    EIN 237000439 · Headquarters: Monroe, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-EZ

  57. International School at Dundee PTA

    EIN 421682765 · Headquarters: Riverside, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

  58. International Society for Islamic Legal Studies

    EIN 202610323 · Headquarters: New Haven, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  59. International Society of Automation

    EIN 066101679 · Headquarters: Wallingford, CT, US · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-N

  60. International Union of Bricklayers & Allied Craftworkers Local 1

    EIN 061478610 · Headquarters: WALLINGFORD, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

  61. International Union of Elevators Loc 91

    EIN 060401156 · Headquarters: EAST HARTFORD, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  62. International Union of Journeymen & Allied Trades

    EIN 710301129 · Headquarters: DANBURY, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

  63. International Union of Journeymen & Allied Trades

    EIN 823161647 · Headquarters: DANBURY, CT, USA · Unknown & Unclassified · Latest available filing year: 2021 · Primary form: IRS Form 990-EZ

  64. International Union of Operating Engineers Local Union 478

    EIN 060401158 · Headquarters: HAMDEN, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  65. International Union of Operating Engineers Welfare Fund 478

    EIN 060662089 · Headquarters: HAMDEN, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

  66. International Union of Painters & Allied Trades District Council 11

    EIN 061269651 · Headquarters: MIDDLETOWN, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  67. International Union of Painters & Allied Trades Local 186

    EIN 060400771 · Headquarters: MIDDLETOWN, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  68. International Union of Painters & Allied Trades Local Union 1274

    EIN 060602657 · Headquarters: MIDDLETOWN, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-EZ

  69. International Union of Painters and Allied Trades Local 1333

    EIN 050275268 · Headquarters: MIDDLETOWN, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-EZ

  70. International Union of Painters and Allied Trades Local No 195

    EIN 050195125 · Headquarters: MIDDLETOWN, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-EZ

  71. International Union of Painters and Allied Trades Local Union 1719

    EIN 061064405 · Headquarters: MIDDLETOWN, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  72. International Union UAW LOCAL 2121

    EIN 010959193 · Headquarters: Gales Ferry, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  73. International Union UAW Local 405

    EIN 060572572 · Headquarters: West Hartford, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  74. International Union Uaw Local 571 Local Union 571 Uaw

    EIN 060790824 · Headquarters: GROTON, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  75. International Union UAW LOCAL 6950

    EIN 474526742 · Headquarters: Storrs, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  76. International Union United Auto Aerospace & Agricultural Workers

    EIN 042461404 · Headquarters: Hartford, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-EZ

  77. International Union United Auto Aerospace & Agricultural Workers

    EIN 060605429 · Headquarters: East Hartford, CT, US · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-N

  78. International Union United Auto Aerospace & Agricultural Workers

    EIN 060632653 · Headquarters: EAST HARTFORD, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-EZ

  79. International Union United Auto Aerospace & Agricultural Workers

    EIN 061294206 · Headquarters: Hartford, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  80. International Union United Auto Aerospace & Agricultural Workers

    EIN 061295954 · Headquarters: Hartford, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  81. International Union United Auto Aerospace & Agricultural Workers

    EIN 061374307 · Headquarters: Hartford, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  82. International Union United Auto Aerospace & Agricultural Workers

    EIN 061374309 · Headquarters: Hartford, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  83. International Union United Auto Aerospace & Agricultural Workers

    EIN 146049340 · Headquarters: EAST HARTFORD, CT, US · Unknown & Unclassified · Latest available filing year: 2021 · Primary form: IRS Form 990-N

  84. International Union United Auto Aerospace & Agricultural Workers

    EIN 237017659 · Headquarters: Hartford, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-EZ

  85. International Union United Auto Aerospace Workers of America

    EIN 061264556 · Headquarters: Hartford, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  86. International Utilities Revenue Protection Association

    EIN 311388229 · Headquarters: SEYMOUR, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  87. International Womens Insolvency & Restructuring Confederation Inc

    EIN 161674502 · Headquarters: Hartford, CT, US · Unknown & Unclassified · Latest available filing year: 2019 · Primary form: IRS Form 990-N

  88. Internationl Association of Lions Clubs

    EIN 061419705 · Headquarters: BETHANY, CT, US · Unknown & Unclassified · Latest available filing year: 2023 · Primary form: IRS Form 990-N

  89. Intl Assoc of Fire Fighters Local 1073

    EIN 066084746 · Headquarters: Middletown, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-EZ

  90. Intl Assoc of Firefighters Local 1739 Ridgefield

    EIN 222994154 · Headquarters: RIDGEFIELD, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

  91. Intl Assoc of Firefighters Local Meriden Firefighters Local 1148

    EIN 066045610 · Headquarters: MERIDEN, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990-EZ

  92. Intl Brotherhood of Teamsters Local Union 145

    EIN 060610540 · Headquarters: BRIDGEPORT, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

  93. Ionic Chapter Order of Demolay

    EIN 264723228 · Headquarters: North Windham, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  94. Iowa Frg

    EIN 851222273 · Headquarters: Groton, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  95. Irish American Historical Society Inc

    EIN 222932494 · Headquarters: Orange, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  96. Irish American Home Society Inc

    EIN 060633969 · Headquarters: GLASTONBURY, CT, USA · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990

  97. Irish Club of Willimantic

    EIN 061325574 · Headquarters: Willimantic, CT, US · Unknown & Unclassified · Latest available filing year: 2014 · Primary form: IRS Form 990-N

  98. Irish History Round Table Inc

    EIN 223191502 · Headquarters: Hamden, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  99. Irish Setter Club of Central Connecticut Inc

    EIN 510141505 · Headquarters: Tariffville, CT, US · Unknown & Unclassified · Latest available filing year: 2025 · Primary form: IRS Form 990-N

  100. Iron Workers' Locals No 15 & 424 Extended Benefit Fund

    EIN 066078910 · Headquarters: CROMWELL, CT, USA · Unknown & Unclassified · Latest available filing year: 2024 · Primary form: IRS Form 990

First page and all pages