'''Decoupling modification''' is a tax terminology resulting from the federal tax law enacted March 109 ,2002, which created a new tax deduction for "bonus depreciation" that threatened to cost states very large amounts of revenue.<ref>http://www.ovguide.com/decoupling-modification-9202a8c04000641f8000000013a2d17b</ref> Federal Bonus Depreciation, Section 168(k) of the Internal Revenue Code,<ref>http://web.utk.edu/~jwachowi/hr3090.html</ref> allows the acceleration of depreciation on federal tax returns, i.e., writing off a higher amount of depreciation for the first year an asset goes into service.<ref>https://revenue-pa.custhelp.com/app/answers/detail/a_id/419/~/what-does-it-mean-to-decouple-from-federal-bonus-depreciation%3F</ref> States that refuse to accept this method of calculating depreciation for state taxes, for example, Iowa and Maryland, publish forms with instructions so stating.<ref>http://iowa.gov/tax/taxlaw/11SF512D.pdf</ref><ref>http://forms.marylandtaxes.com/current_forms/500dm.pdf</ref>
