Final answer:
Fred can deduct up to 100% of his AGI for cash contributions to a public charity for AMT purposes. Since his AGI is $150,000, and his contribution was $90,000, his charitable contribution deduction for AMT purposes is the full $90,000.
Step-by-step explanation:
The student's question pertains to calculating the charitable contribution deduction for Alternative Minimum Tax (AMT) purposes for someone named Fred, who has an Adjusted Gross Income (AGI) of $150,000 and has contributed $90,000 in cash to a public charity.
For AMT purposes, the deduction for charitable contributions is generally the same as for regular tax purposes. Assuming Fred's contribution meets all the necessary requirements for deductibility, for the tax year 2021, an individual can deduct contributions up to 100% of their AGI when the contribution is made in cash to a public charity. Since Fred's contribution does not exceed his AGI, his charitable contribution deduction for AMT purposes would be the full amount contributed, which is $90,000.