Dear Liz: I am confused regarding my ability to take advantage of the American Opportunity Credit for college expenses in filing my 2014 tax return.

My accountant told me I didn’t qualify because my adjusted gross income exceeds $80,000. Yet when I researched on the IRS website, I seem to qualify. I paid qualified education expenses for my son to get an MBA and am claiming him as a dependent on my return, since he is unemployed and I support him. My adjusted gross income was $84,905.

The IRS rules discuss modified adjusted gross income less than $90,000. Is my accountant thinking of another tax credit that I don’t qualify for? Can I take advantage of any credit for providing educational expenses for my son to obtain a graduate degree? I filed for an extension in order to resolve this issue.

Answer: Education tax breaks can be baffling because each has different income limits, eligibility requirements and qualifying expenses.

Three of them — the American Opportunity Credit, the Lifetime Learning Credit and the tuition and fees deduction — are mutually exclusive. That means you can take only one per year, and you can’t use any of them for expenses paid with a tax-free 529 plan withdrawal.

It’s no wonder that many people who may be eligible to take these breaks don’t take advantage of them, even though they could shave thousands of dollars off their tax bills.

The American Opportunity Credit is usually the most valuable credit. It reduces taxes by up to $2,500 per student and is 40% refundable, which means people can get up to $1,000 back even if they don’t have any taxes to offset.

But the credit can’t be claimed for more than four years, and any year in which the old Hope Credit was claimed counts toward that limit. Since your son was in graduate school, it’s possible you already used up your ability to claim the credit.

You can qualify for the full tax break if your modified adjusted gross income is below $80,000 as a single filer or $160,000 for a married couple filing jointly. The credit gets smaller as your income goes up. After $90,000 for singles — and $180,000 for a married couple filing jointly — the tax break is no longer available.

If you can’t take the credit, your son might be able to claim it — if he had taxable income last year and you opt not to take a dependency exemption for him. Discuss this possibility with your tax pro.

You make too much money for the other two options: the Lifetime Learning Credit and the tuition and fees deduction. The Lifetime Learning Credit offsets 20% of tuition and certain other required expenses up to $2,000 per tax return.

In 2014, the credit was gradually reduced for modified adjusted gross incomes between $54,000 and $64,000 for singles, and $108,000 and $128,000 for married couples filing jointly.

The tuition and fees deduction reduces taxable income by a maximum of $4,000 for incomes up to $65,000 for single filers and $130,000 for joint filers, and by up to $2,000 for incomes over $65,000 for singles and $130,000 for joint filers. There’s no deduction for incomes over $80,000 for singles and $160,000 for joint filers.