In the complex world of tax compliance, electronic filing for Affordable Care Act (ACA) information returns is a critical requirement for insurers, employers, and software developers. IRS Publication 5164, titled “Test Package for Electronic Filers of Affordable Care Act (ACA) Information Returns (AIR),” serves as the definitive resource for ensuring your systems are ready for seamless submissions through the ACA Information Returns (AIR) system. Updated for Processing Year 2026 (covering Tax Year 2025), this publication outlines the Assurance Testing System (AATS) processes, scenarios, and guidelines to help filers avoid errors and achieve compliance. Whether you’re a software developer building transmission tools or a transmitter preparing to file Forms 1094-B, 1095-B, 1094-C, and 1095-C, understanding this document is key to successful electronic filing.
This article breaks down the essentials of IRS Publication 5164, including its purpose, testing requirements, and practical tips for ACA electronic filers. By following these guidelines, you can streamline your preparation and ensure your ACA information returns are processed efficiently by the IRS.
What Is IRS Publication 5164 and Why Does It Matter?
IRS Publication 5164 provides a comprehensive test package designed specifically for electronic filers of ACA-related information returns. It focuses on the ACA Assurance Testing System (AATS), which is mandatory for certain participants to verify that their software and transmission methods meet IRS standards before going live in production.
Background and Purpose
Under the Affordable Care Act, entities like insurance providers, self-insured employers, and Applicable Large Employers (ALEs) must report health coverage information to the IRS using specific forms. Publication 5164 ensures that electronic submissions via the AIR system are accurate, secure, and compliant. It includes general testing information, program-specific scenarios, and validation rules to prevent common issues like schema errors or invalid data formats.
The publication covers forms for Tax Year 2025:
- Form 1094-B and 1095-B: Used by providers of minimum essential coverage to report on individuals’ health insurance.
- Form 1094-C and 1095-C: Employed by ALEs to detail offers of employer-sponsored coverage and enrollment details.
Without successful AATS completion, your Transmitter Control Code (TCC) remains in “Test” status, blocking production filings. This makes the test package indispensable for avoiding delays, penalties, and rework during tax season.
Key References in Publication 5164
The document cross-references other essential IRS resources, such as:
- Publication 5165: Guide for Electronically Filing ACA Information Returns.
- Publication 5308: Automated Enrollment for ACA Providers.
- Publication 5258: ACA Transmitter Control Code Application Procedures.
These complementary guides provide deeper insights into XML schemas, business rules, and application processes.
Who Must Test Using the ACA Assurance Testing System (AATS)?
Not every filer needs to complete full AATS scenarios, but specific roles have mandatory requirements.
Software Developers
If you’re developing software for transmitting ACA returns, you must pass AATS for each tax year and form type you support. Retesting isn’t required if you passed the previous year and no new forms are added. Testing validates schema compliance, business rules, and transmission formats.
Transmitters and Issuers
Transmitters (including issuers who transmit their own returns) must complete a one-time communication test in their first year of filing. This involves submitting one AATS scenario using pre-approved software. Software developers who also act as transmitters are exempt from separate testing.
When and Why Test?
- Timing: AATS opens in early November for the upcoming processing year. First-time filers should start early to allow time for corrections.
- Purpose: Testing confirms the IRS can receive, process, and acknowledge your submissions without issues, reducing the risk of rejections in production.
Important: Use only mock Taxpayer Identification Numbers (TINs) and Social Security Numbers (SSNs) from designated ranges provided in the publication. Live data is strictly prohibited and will result in rejection.
Overview of AATS Transmissions and Processes
Publication 5164 details the end-to-end customer experience for AATS submissions.
Transmission Channels
You can submit test files through two channels:
- Issuer Services Portal – User Interface (ISS-UI): A web-based upload system for XML files, ideal for smaller volumes.
- Issuer Services Portal – Application to Application (ISS-A2A): A SOAP-based method with Message Transmission Optimization Mechanism (MTOM) attachments, suited for automated, high-volume transmissions.
Both require a valid TCC and must match the channel you’ll use in production.
Manifest Validation and Receipt ID
Every test transmission includes a manifest with key elements:
- TestFileCd: Set to “T” for test mode.
- SoftwareId: Must be in Test or Production status.
- FormTypeCd: Specifies “1094/1095-B” or “1094/1095-C”.
- TCC: Active and configured for the form type.
Upon submission, you’ll receive a Receipt ID if initial checks pass. This ID is used to retrieve acknowledgements, which indicate statuses like “Accepted,” “Rejected,” or “Accepted with Errors.” In AATS, resubmit rejected files as originals with a new Unique Transmission ID (uTID).
Acknowledgement Files
Acknowledgements detail validation results. An “Accepted” status means no errors; contact the IRS Help Desk (1-866-937-4130) with your Receipt ID to update your TCC to Production. Wait 48 hours after approval before filing live returns.
Testing Guidelines and Scenarios for Software Developers
Section 5 of Publication 5164 provides step-by-step guidance for developers.
Steps to Pass AATS
- Create an e-Services account with two-factor authentication.
- Apply for a TCC via the ACA Application.
- Select and prepare required scenarios.
- Submit error-free transmissions.
- Verify “Accepted” status and notify the Help Desk.
Required Scenarios
Scenarios test specific data sets:
- For B Forms: Scenario 1 (including sub-scenarios 1-0, 1-1, 1-2).
- For C Forms: Scenarios 3 and 5 (with sub-scenarios).
- Optional: Correction scenarios like 1C-0 or 4C-0.
Data must match exactly, using mock TINs (e.g., EIN 00-0000001 with name control “HELP”).
Correction Testing
For corrections:
- Use TransmissionTypeCd = “C”.
- Include CorrectedUniqueSubmissionID (uSID) or CorrectedUniqueRecordId (CuRID) from the original acknowledgement. This is optional but recommended for comprehensive testing.
Formatting and Signatures
Follow XML e-file types for entities. No electronic signatures are needed for 1094 forms, but A2A requires x.509 digital certificates.
Communication Test for Transmitters
Transmitters submit one scenario using passed software. Success (even with minor errors) qualifies you for Production status after Help Desk review. No retesting for subsequent years unless adding new forms.
Additional Resources and Updates for 2026
For XML resources, the publication references W3C standards and tools like XMLSpy. Stay current by checking the IRS AIR page for known issues and scenario instructions.
As of February 2026, the October 2024 version of Publication 5164 remains the latest, with no major changes announced. Monitor IRS.gov for any updates related to Tax Year 2025 filings.
Conclusion: Prepare for Success with IRS Publication 5164
Mastering IRS Publication 5164 is crucial for anyone involved in ACA electronic filing. By completing AATS and following the outlined procedures, you ensure compliance, minimize errors, and facilitate smooth information return submissions. Download the PDF from the official IRS site and start testing today to stay ahead in 2026. For personalized assistance, contact the IRS Help Desk or consult a tax professional.