IRS Publication 5258 – IRS Forms, Instructions, Pubs 2026 – The Affordable Care Act (ACA) mandates that certain entities report health insurance coverage information to the IRS using specific forms. For those navigating the electronic submission process, IRS Publication 5258 serves as an essential resource. Titled “Affordable Care Act (ACA) Information Returns (AIR) Submission Composition and Reference Guide,” this document provides detailed instructions on composing and submitting ACA-related information returns through the IRS’s AIR system. Updated for December 2025, it ensures compliance for tax year 2025 filings processed in 2026. Whether you’re an employer, insurance carrier, or software developer, understanding this guide is crucial for accurate and efficient reporting.
What Is IRS Publication 5258?
IRS Publication 5258 is a technical reference guide designed to help transmitters compose and submit ACA information returns electronically. It focuses on the AIR system’s requirements for Forms 1094-B, 1095-B, 1094-C, and 1095-C, which report on health coverage provided under the ACA. The publication outlines the structure of submissions, including XML schemas, web service definitions, and error resolution processes. With a revision date of December 2025, it incorporates the latest updates to align with current IRS standards, making it indispensable for entities required to file 10 or more returns electronically.
Key audiences include:
- Employers providing health insurance.
- Insurance issuers and carriers.
- Self-insured companies.
- Government agencies.
- Third-party transmitters and software developers.
The guide emphasizes the integration of IRS-provided tools and code samples to facilitate seamless submissions.
Purpose of Publication 5258 in ACA Reporting
The primary goal of Publication 5258 is to deliver clear guidance on the applications, infrastructure, and processes needed for ACA information returns. Under the ACA, businesses and insurers must report coverage details to verify compliance with the individual and employer mandates. The AIR system streamlines this by allowing electronic filings, which are mandatory for filers with 10 or more returns starting from January 1, 2024.
The publication addresses:
- Composition of Submissions: How to structure XML files for accurate data transmission.
- Reference Materials: Schemas, WSDL files, and checklists for validation.
- Error Handling: Identifying and correcting issues in submissions.
- Updates for Current Processing Years: Incorporating changes like new schema guidance and correction procedures for Forms 1094-C and 1095-C.
By following this guide, filers can avoid common pitfalls, such as invalid formats or incomplete data, ensuring timely acceptance by the IRS.
Key Sections and Components of Publication 5258
While the full 160-page document provides in-depth technical details, here are the core sections based on the latest revision:
1. Introduction to AIR Project
This section overviews the ACA Information Returns (AIR) system’s role in delivering secure submission infrastructure. It explains the project’s responsibility for supporting electronic filing processes.
2. Submission Channels
- UI Channel: Browser-based interface for uploading forms and testing scenarios via the ACA Assurance Testing System (AATS).
- A2A Channel: Application-to-Application method for automated submissions, including certificate uploads and enrollment guidance.
3. Composing ACA Information Returns
Details on XML structure for Forms 1094/1095-B and 1094/1095-C. Includes integration of IRS code samples and references to schemas/WSDL for tax year 2025.
4. Testing and Validation
Guidance on using AATS for software testing, communications tests, and scenario validation. Software developers must obtain a new Software ID annually and pass required tests.
5. Transmitting and Correcting Returns
Step-by-step instructions for submissions, acknowledgements, and corrections. Emphasizes waiting periods for status checks and using correct endpoints for AATS vs. production environments.
6. Error Codes and Acknowledgements
References to Publication 5165 for detailed acknowledgement files and error resolution.
7. Checklists and References
End-of-document checklists for transmitters, plus updates to sections like A2A channels and correction transmissions.
How to Apply for a Transmitter Control Code (TCC) Using Publication 5258?
Before submitting via AIR, obtain a TCC. Publication 5258 references the application process, which requires an ID.me account and e-Services registration. Steps include:
- Selecting roles (e.g., transmitter, issuer).
- Passing AATS tests for developers.
- Completing communications tests for transmitters.
- Signing agreements with a PIN.
TCCs are issued online and by mail, essential for both testing and production filings.
Related IRS Publications and Resources
Publication 5258 complements other guides:
- Publication 5165: Electronic filing guide for software developers and transmitters.
- Publication 5164: Test packages for ACA filers.
- Publication 5308: Automated enrollment for external systems.
For the latest version, download from IRS.gov. Contact the AIR Help Desk at 866-937-4130 for support.
Why Compliance with Publication 5258 Matters in 2026?
With the electronic filing threshold lowered to 10 returns, more entities must use AIR. Non-compliance can result in penalties. By leveraging Publication 5258, filers ensure accurate reporting, reducing errors and processing delays. Stay updated, as the IRS periodically revises the guide to reflect regulatory changes.
For the most current information, visit the IRS AIR page or download the PDF directly from IRS.gov. This guide empowers you to handle ACA submissions confidently in processing year 2026.