The links below provide information and technical guidance for Software Developers and Transmitters who are interested in developing software for the Modernized e-File (MeF) Form 1065 for Tax Year (TY) 2019.

Developers and other Authorized IRS e-file Providers can find information on e-filing returns through MeF in the Publication 4163PDF and Publication 4164PDF. Test Scenarios for Form 1065 can be found on the Modernized e-File (MeF) Assurance Testing System (ATS) Page.

XML Schemas, Business Rules and Release Memos - Throughout the year, multiple versions of these documents may be in use at the same time. Special attention should be paid to the Release Memo issue date and the projected start and end dates for Assurance Testing System (ATS) and Production.

Form 1065 Schemas and Business Rules are now distributed through the Registered User Portal and your e-services mailbox. This mailbox is part of the Secure Object Repository (SOR). Users will access their mailbox in their existing e-services account to pick up the Schema and Business Rules packages.

Tax Year 2019 Documents

Form 1065 links to TY2019 Release Memos


Available Date

ATS Date

Production Date


2019v5.3 10/16/2020

Start: 11/22/2020
End: TBD

Start: 01/08/2021
End: TBD

03/31/2022 Business Rules updates provided 

Business Rule updates provided 09/23/21, available in ATS 10/12/2021, available in production in PY2022.

Business Rules updates provided 8/19/21, available in ATS 10/12/2021, available in production in PY2022.

11/16/2020 Business Rules updates provided

2019v5.2 04/13/2020 Start: 06/07/2020
End: TBD
Start: 06/21/2020

End: TBD

2019v5.1 02/12/2020 Start: 03/08/2020

End: TBD

Start: 03/22/2020

End: TBD

2019v5.0 12/05/2019 Start: 12/29/2019
End: TBD
Start: 01/07/2020

End: TBD

01/27/2020 Business rule updates provided

Current Valid XML Schemas and Business Rules for 1065 Modernized e-File (MeF)

Modernized e-File (MeF) Schemas and Business Rules