A
contribution that one may place into an
IRA,
401(k), or other
retirement plan each year that can reduce one's
taxable income by the same amount. That is, the deductible contribution is the portion of one's retirement contribution that is
tax deductible. The
IRS generally sets the limits on deductible contributions. For example, the limit on deductible contributions for 401(k) plans was $16,500 in 2009.