TY 2021 Valid XML Schemas and Business Rules for Form 1065 Modernized e-File (MeF)


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) 2021.

Developers and other Authorized IRS e-file Providers can find information on e-filing returns through MeF in the Publication 4163  PDF and Publication 4164 PDF. 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 Memorandum - 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 2021 Documents

Form 1065 links to TY2021 Release Memos


Available Date

ATS Date

Production Date


2021v4.2 Draft 12/22/2021 Not Valid for ATS Not Valid for Production 12/22/21
An early look of Tax Year 2021/ Processing Year 2022 Form 1065 Schedules K-2 and K-3 schema only. Related business rules will be made available later.
2021v4.1 11/12/2021

Start: 12/12/2021
End: TBD

Start: 01/07/2022
End: TBD

2021v4.0 10/14/2021 Start: 11/21/2021
End: TBD
Start: 01/07/2022
End: TBD
2021v3.0 09/02/2021 Start: 10/12/2021
End: 11/20/2021
Not Valid for Production  
2021v2.0 07/22/2021 Not Valid For ATS Not Valid for Production  
2021v1.0 06/10/2021

Not Valid For ATS

Not Valid for Production  

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

Modernized e-File (MeF) Schemas and Business Rules