The IRS has updated Publication 5258. Publication 5258 is the ACA Information Returns Submission Composition and Reference Guide and is used to electronically file Forms 1094 B and C, and Form 1095 B and C with the IRS.
Tables 5-4, 5-8, and 5-10 were updated to remove a statement that said “UserID is not required for UI submissions.” Section 5.3.1.1 was updated to include a missing “Al” for Algorithm, and Section 5.3.1.1 and 5.3.1.4 updated canonicalization method algorithms and the ACA Security Header User ID.
To view the updated Publication 5258, please click here.