Which of the following can be subtracted from total income to calculate adjusted gross income?

Adjusted Gross Income (AGI) is calculated by taking total income and deducting specific allowable expenses. Among the choices listed, educator expenses are a direct deduction that can be made to reduce total income when calculating AGI.

Educator expenses specifically refer to out-of-pocket costs incurred by teachers and qualified educators for supplies, materials, and other classroom-related expenses. This deduction is particularly beneficial because it allows educators to reduce their taxable income without needing to itemize deductions, making it accessible for many taxpayers.

The other options provided do not qualify as deductions for calculating AGI. Rent payments are generally considered personal living expenses and are not deductible in this context. Medical expenses can only be deducted when they exceed a certain percentage of adjusted gross income and are typically considered itemized deductions rather than an AGI adjustment. Mortgage interest, while deductible for homeowners, falls under itemized deductions and does not directly reduce gross income to determine AGI. Thus, educator expenses stand out as the correct choice for adjusting gross income.