ATS opens Oct. 10, 2025, for filing season 2026.
ATS is scheduled to open Oct. 10, 2025, 9 a.m. Eastern time. Testing will begin Oct. 14, 2025, 9 a.m. Eastern time. If you submit the scenarios for review earlier than Oct. 14, they will be treated as though they were received on Oct. 14.
Modernized e-File (MeF) ATS calls:
When: 10/15/2025 and 10/16/2025
Call logs
Modernized e-File (MeF) Assurance Testing System (ATS) updates
The Modernized e-File (MeF) Assurance Testing System (ATS) scenarios and known issues are listed in the table below.
| ATS scenario form | Tax period | ATS scenario known issues and solutions | Comments |
|---|---|---|---|
| 709 | 2025 | 709 ATS known issues | |
| 720 | 2026 | 720 ATS known issues | |
| 94x form family (Annual) | 2025 | 94x ATS known issues | |
| 94x form family (Quarterly) | 2026 | 94x ATS known issues | |
| 990 form family/1120 POL | 2025 | 990 ATS known issues | |
| 1040 series and extensions | 2025 | 1040 series and extensions ATS known issues XLSX |
11/03/2025 – The 1040 series and extensions ATS known issues and solutions file has been updated 10/15/2025- The 1040 series and extensions ATS known issues and solutions file has been updated 10/6/2025 – The 1040 series and extensions ATS known issues and solutions file has been updated. |
| 1041 | 2025 | 1041 ATS known issues | |
| 1042 | 2025 | 1042 ATS known issues | |
| 1065 form family | 2025 | 1065 ATS known issues XLS |
10/22/2025 – The 1065 form family ATS known issues and solutions file has been updated. 10/15/2025 – The 1065 form family ATS known issues and solutions file has been updated. |
| 1120 form family | 2025 | 1120 ATS known issues XLS |
10/3/2025 - The 1120 form family ATS known issues and solutions file has been updated. 10/8/2025 – The 1120 form family ATS known issues and solutions file has been updated. 10/30/2025 - The 1120 form family ATS known issues and solutions file has been updated. |
| 1139 | 2025 | 1139 ATS known issues | |
| 2290 | 2025 | 2290 ATS known issues | |
| 2290 | 2026 | 2290 ATS known issues | |
| 7004 | 2025 | 7004 ATS known issues | |
| 8849 | 2026 | 8849 ATS known issues PDF | |
| 8868 | 2025 | 8868 ATS known issues |
| ATS scenario form | Tax period | ATS scenario known issues and solutions | Comments |
|---|---|---|---|
| 709 | 2024 | 709 ATS known issues | |
| 720 | 2025 | 720 ATS known issues | |
| 94x form family (Annual) | 2024 | 94x ATS known issues | |
| 94x form family (Quarterly) | 2025 | 94x ATS known issues XLS | |
| 990 form family/1120 POL | 2024 | 990 ATS known issues | |
| 1040 series and extensions | 2024 | 1040 series and extensions ATS known issues XLSX |
1/21/2025 – The 1040 series and extensions ATS known issues and solutions file has been updated. 12/4/2024 – The 1040 series and extensions ATS known issues and solutions file has been updated. 11/5/2024 – The 1040 series and extensions ATS known issues and solutions file has been updated. 11/5/2024 – The 1040 MeF series ATS scenario 5 was updated to reflect the Section 508 compliant file. No changes were made to the information or figures within the scenario. 10/29/2024 – The 1040 series and extensions ATS known issues and solutions file has been updated. 10/22/2024 – The 1040 series and extensions ATS known issues and solutions file has been updated. 10/10/2024 – The 1040 series and extensions ATS known issues and solutions file has been updated. |
| 1041 | 2024 | 1041 ATS known issues PDF | |
| 1042 | 2024 | 1042 ATS known issues | |
| 1065 form family | 2024 | 1065 ATS known issues XLS | |
| 1120 form family | 2024 | 1120 ATS known issues | |
| 2290 | 2024 | 2290 ATS known issues | |
| 2290 | 2025 | 2290 ATS known issues | |
| 7004 | 2024 | 7004 ATS known issues | |
| 8849 | 2025 | 8849 ATS known issues PDF | |
| 8868 | 2024 | 8868 ATS known issues |
| ATS scenario form | Tax period | ATS scenario known issues and solutions | Comments |
|---|---|---|---|
| 720 | 2024 | 720 ATS known issues | |
| 94x form family (2023) | 2023 | 94x ATS known issues XLS | 05/29/2024 – Form 943-X scenario posted to the TY2023 ATS page. |
| 94x form family (2024) | 2024 | 94x ATS known issues XLS | 05/29/2024 – Form 941-X scenario posted to the TY2024 ATS page. |
| 990 form family/1120 POL | 2023 | 990 ATS known issues | |
| 1040 series and extensions | 2023 | 1040 series and extensions ATS known issues XLSX |
12/19/2023 – 1040 series and extensions ATS known issues and solutions file updated. 12/6/2023 – 1040 series and extensions ATS known issues and solutions file updated. 11/29/2023 – 1040 series and extensions ATS known issues and solutions file updated. 11/16/2023 – 1040 series and extensions ATS known issues and solutions file updated. 11/7/2023 – 1040 series and extensions ATS known issues and solutions file updated. 11/1/2023 – 1040 series and extensions ATS known issues and solutions file updated. |
| 1041 | 2023 | 1041 ATS known issues | |
| 1042 | 2023 | 1042 ATS known issues | |
| 1065 form family | 2023 | 1065 ATS known issues PDF | |
| 1120 form family | 2023 | 1120 ATS known issues XLS | |
| 2290 | 2023 | 2290 ATS known issues | |
| 2290 | 2024 | 2290 ATS known issues | |
| 7004 | 2023 | 7004 ATS known issues | |
| 8849 | 2024 | 8849 ATS known issues | |
| 8868 | 2023 | 8868 ATS known issues |
| ATS scenario form | Tax period | ATS scenario known issues and solutions | Comments |
|---|---|---|---|
| 720 | 2023 | 720 ATS known issues | |
| 94x form family (2022) | 2022 | 94x ATS known issues | |
| 94x form family (2023) | 2023 | 94x ATS known issues | |
| 990 form family/1120 POL | 2022 | 990 ATS known issues | |
| 1040 series and extensions | 2022 | 1040 series and extensions ATS known issues XLSX |
11/22/2022 – 1040 ATS known issues and solutions has been updated. 11/22/2022 – All 1040 series and extensions ATS scenarios for processing year 2023 are available. 11/8/2022 – 1040 ATS scenario known issues and solutions has been updated. |
| 1041 | 2022 | 1041 ATS known issues XLS | |
| 1042 | 2022 | 1042 ATS known issues XLSX | |
| 1065 form family | 2022 | 1065 ATS known issues XLS | |
| 1120 form family | 2022 | 1120 ATS known issues XLS | |
| 2290 (2023) | 2023
2022 |
2290 ATS known issues | |
| 7004 | 2022 | 7004 ATS known issues | |
| 8849 | 2023 | 8849 ATS known issues | |
| 8868 | 2022 | 8868 ATS known issues |
- Find all MeF publications on the MeF user guides and publications page.
- Information on the distribution of Modernized e-File (MeF) new web service definition language (WSDL) can be found on the Modernized e-File (MeF) status page.