Mathematical or clerical error summary assessment procedures. This ruling clarifies whether the mathematical or clerical error assessment procedures of section 6213(b) of the Code apply when a taxpayer files an income tax return that reports income in an amount different from that reported on a W-2.

Final regulations under section 179 of the Code provide rules for making and revoking elections to expense the cost of certain depreciable business property. The regulations apply for property placed in service in taxable years beginning after 2002 and before 2008.

This document contains corrections to temporary regulations (T.D. 9186, 2005-13 I.R.B. 790) modifying the rules relating to qualified amended returns by providing additional circumstances that end the period when a taxpayer may file an amended return that constitutes a qualified amended return.