Why this one is different
Most updates change a requirement. This one changes the form the requirement is recorded on, which means it reaches into every document, checklist and system that ever named an appraisal form by number.
The mandatory date is hard. A UAD 2.6 report submitted to UCDP on or after November 2, 2026 returns a Fatal message and the submission fails. UAD 2.6 revisions remain possible until May 2027, but new reports do not.
What makes it easy to get wrong
Freddie Mac currently publishes affected Guide sections in two versions at once — the one in force today, and the UAD 3.6 version that takes over on November 2. Both are real regulator text and both read like current policy. Our reg pages label the pending version explicitly; the source documents largely do not.
That is the specific failure this kit is built to catch: an assistant, or a person, reading the November version and applying it in September.
The source material
The GSEs publish the redesign as a set of numbered appendices, not as a rule. Three of them are the substance and all three are in the corpus verbatim:
| Appendix B-1 Implementation Guide v1.4 | 401 pages — what a compliant report must contain |
| Appendix F-1 Reference Guide v1.4 | 378 pages — field-by-field reference |
| Appendix E Report Style Guide | 92 pages — how the report presents |
Also published, and worth knowing exists: Appendix G-1, a Redesign-to-Legacy UAD cross reference that maps each new field back to its UAD 2.6 equivalent, and Appendix D-1, sample use cases with actual XML. Those are the artifacts to hand an engineering team.
Who is actually behind this
FHFA directs it; Fannie Mae and Freddie Mac implement it through the Uniform Mortgage Data Program, with FHA aligning. There is no single regulator to watch, which is part of why it is easy to miss.