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Tax year 2026 Modernized e-File schema and business rules for individual tax returns and extensions

 

The tables below provide links to the tax year 2026 release memorandum, extensible markup language schema, and business rules for the Modernized e-File (MeF) 1040 series and extensions.

Throughout the year, multiple versions of schema and business rules may be in use at the same time. For each version, the tables below reflect the effective dates in the Assurance Testing System (ATS) and Production System.

Tax year 2026 documents

Tax year 2026 Form 1040 series

VersionDate available in SOR *ATS dateProduction dateComments
2026v1.05/28/2026Not valid for ATSNot valid for production-
2026v2.07/02/2026Not valid for ATSNot valid for production-
2026v3.08/13/2026TBDNot valid for production-

Tax year 2026 Form 4868

VersionDate available in SOR *ATS dateProduction dateComments
2026v1.05/28/2026Not valid for ATSNot valid for production-
2026v2.07/02/2026TBDTBD-

Tax year 2026 Form 2350

VersionDate available in SOR *ATS dateProduction dateComments
2026v1.05/28/2026Not valid for ATSNot valid for production-
2026v2.07/02/2026TBDTBD-

Form 9465

VersionDate available in SOR *ATS dateProduction dateComments
CUv28.15/28/2026Not valid for ATSNot valid for production-
CUv29.07/02/2026TBDTBD-

Form 56

VersionDate available in SOR *ATS dateProduction dateComments
CUv24.15/28/2026TBDTBD-

* Secure Object Repository (SOR)

Valid XML schemas and business rules for 1040 series

Modernized e-File (MeF) schemas and business rules