This lesson is best used after studying Federal Income Taxation: Taxable Income and Tax Computation, in class. The lesson includes problem sets to work through, allowing you to apply the Code and Regs. to a variety of situations involving personal and dependency exemptions, under Internal Revenue Code sections 151 and 152.
For the taxable years 2018 through 2025, Code § 151(d)(5) has reduced all personal and dependency exemptions to zero.
Therefore, until 2026, the following lesson is for historical information and does not reflect current law's disallowance of personal and dependency exemptions. Other Code sections do, however, still rely on the definition of dependent found in § 152 - for example, § 32 (earned income tax credit) and § 213 (deduction for medical expenses).