Which type of IRA does not offer deductible contributions as adjustments to income?

The correct answer is a Roth IRA. Contributions made to a Roth IRA are not tax-deductible; hence, they do not provide an adjustment to income when calculating taxable income. This feature distinguishes Roth IRAs from Traditional IRAs, where contributions can often be deducted from taxable income, reducing the taxpayer's liability for the year in which the contributions are made.

With a Roth IRA, the money contributed grows tax-free, and qualified withdrawals in retirement are also tax-free, which is a significant advantage for individuals who anticipate being in a higher tax bracket during retirement. This tax treatment incentivizes saving for retirement, even if the immediate tax benefit is not available through a deduction.

In contrast, Traditional IRAs offer the opportunity for tax-deductible contributions, which can lower taxable income in the year of contribution, making them an appealing option for individuals looking to reduce their current tax burden. Simple IRAs and Coverdell education savings accounts have different rules regarding deductions and contributions, further distinguishing them from Roth IRAs.