What factor determines the carryover available for future years from Alternative Minimum Tax credits?

The correct choice focuses on the difference between regular tax and tentative minimum tax, which is a critical aspect in determining the carryover of Alternative Minimum Tax (AMT) credits to future years. AMT credits arise when a taxpayer pays AMT in a given year and are generally allowed to offset regular tax in subsequent years.

To compute the carryover available for future years, the relevant figure is the difference between what a taxpayer is required to pay under the regular tax system and what they would pay if they were under the AMT system. This difference illustrates how much additional tax has been paid due to the AMT and determines the credits that can be carried forward. Essentially, if the tentative minimum tax exceeds the regular tax, the excess reflects AMT credits that can be utilized in later years when a taxpayer's regular tax liability might be higher than their tentative minimum tax.

While other factors like the amount of regular tax, long-term capital gains, or previous year’s tax liabilities play important roles in various tax calculations, they do not directly influence the calculation of AMT credit carryover, as this calculation specifically hinges on the interaction between the regular tax and tentative minimum tax amounts. Thus, the focus on the difference provides a clear and precise means of establishing