What is the Internal Revenue Manual?
The Internal Revenue Manual is publicly available.
It contains information of a general nature.
The Internal Revenue Manual is an internal operating manual which provides policies and procedures for employees of the IRS.
Because the IRM is published for mostly internal use, it is not considered precedential or authoritative, but can be useful in gaining information about the Service's procedures and policies. The IRM does not constitute substantial authority for avoiding the substantial understatement penalty.