Tax year 2026 Form 1120 Modernized e-File (MeF) Assurance Testing System (ATS) information

The tax year 2026 Form 1120 Modernized e-File (MeF) Assurance Testing System (ATS) information is contained below.

If you support these forms, you will need to contact the e-Help Desk for testing. Please monitor this page for any ATS scenario updates.

TY 2026 1120 MeF ATS scenarios

• 1120 MeF ATS scenario 1 (Form 1120) PDF (9/25/2026)
• 1120 MeF ATS alternate scenario 1 (Form 1120) PDF (9/25/2026)
• 1120 MeF ATS scenario 2 (Form 1120) PDF (9/23/2026)
• 1120 MeF ATS scenario 3 (Form 1120) PDF (9/23/2026)
• 1120 MeF ATS scenario 4 (Form 1120) - Coming soon 
• 1120-S MeF ATS scenario 5 (Form 1120-S) PDF (9/23/2026)
• 1120-S MeF ATS scenario 6 (Form 1120-S) - Coming soon
• 1120-S MeF ATS scenario 7 (Form 1120-S) – Coming soon
• 1120-S MeF ATS scenario 8 (Form 1120-S) PDF (9/25/2026)
• 1120-F MeF ATS scenario 9 (Form 1120-F) PDF (9/23/2026)
• 1120-H MeF ATS scenario 10 (Form 1120-H) PDF (9/24/2026) 
• 1120 MeF ATS scenario 11 (Form 1120) – Coming soon
• 1120-L MeF ATS scenario 12 (Form 1120-L) PDF (9/24/2026)
• 1120-PC MeF ATS scenario 13 (Form 1120-PC) PDF (9/24/2026)
• 1120-REIT MeF ATS scenario 14 (Form 1120-REIT) PDF (9/24/2026)
• 1120-RIC MeF ATS scenario 15 (Form 1120-RIC) PDF (9/24/2026)

For information and questions regarding ATS, please contact the e-Help Desk at 866-255-0654.

Modernized e-File (MeF) Assurance Testing System (ATS)

2026 valid XML schemas and business rules for 1120, 1120-F, 1120-H, 1120-L, 1120-PC, 1120-REIT, 1120-RIC and 1120-S Modernized e-File (MeF)