Ask the Editor, June 6: Questions on Hobby Losses, Medicare

Each week, in our Ask the Editor series, Joy Taylor, The Kiplinger Tax Letter Editor, answers questions on topics submitted by readers. This week, she’s looking at questions on hobby losses, I bonds and Medicare premiums. (Get a free issue of The Kiplinger Tax Letter or subscribe.)

1. Hobby Loss or Business Loss

Question: I own a dog-breeding business, and for the past few years, I have reported losses from the business on Schedule C of my Form 1040. What are the odds that the IRS will audit my return?

Joy Taylor: The odds of an IRS audit are quite low for most people. In recent years, the IRS has audited significantly less than 1% of all individual tax returns, and we expect that number will remain low for the foreseeable future. However, there are some audit red flags that could increase the chance of drawing unwanted attention from the IRS. One of those is deducting a hobby loss. Filers who report multiple years of big losses on Schedule C of Form 1040, run an activity that sounds like a hobby, and have lots of income from other sources that the losses offset are prime IRS audit targets.

To deduct a Schedule C loss, you must show that the activity is a business. It needs to be conducted with continuity and regularity in a businesslike manner, and you must have a reasonable, good-faith objective of making a profit from it. The IRS’s regulations provide a safe harbor. If your activity generates profit in three out of five consecutive years (or two out of seven years for horse breeding), the law presumes you’re in business to make a profit unless the IRS establishes otherwise. The hobby-business analysis is trickier if you can’t meet the safe harbor. That’s because the determination of whether an activity is properly categorized as a hobby or a business is then based on each taxpayer’s facts and circumstances. The IRS and the courts generally look at the following nine factors (note that no one factor is determinative, but some are routinely given more weight):

• Expertise of the taxpayer and advisers
• Manner in which one carries on the activity
• Time and effort devoted to the venture
• Expectation that assets used in the activity may appreciate
• History of income and losses (the more years of large, consecutive losses, the harder it is to demonstrate a profit motive unless the activity is still in its start-up stage)
• Amount of occasional profits
• Success in carrying on other activities
• Elements of personal pleasure or recreation that one gets from the activity
• Whether the taxpayer has substantial income from other sources, such as wages, other business income, retirement income or investment income

For more information, here is an online story that I wrote on the hobby loss rules

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2. I Bonds and College Education

Question: I have owned Series I bonds for many years. I heard that if I cash in the bonds and use the bond proceeds for higher education for my children, then I won’t have to pay tax on the interest when I cash my I bonds in. Is that true?

Joy Taylor: I bond buyers have a choice when they acquire the bonds. They can pay federal income tax each year on the interest earned or defer the tax bill to the end. Most people choose the latter, which is what I assume you did. Thus, you would generally report interest income on your Form 1040 for the year the bonds mature or when they are cashed in, whichever comes first.

One way to avoid paying federal income tax on accrued I bond interest is to cash in the bonds on or before the maturity date and use the proceeds to help pay for college or other higher education expenses for you, your spouse or your dependent. Note that there are lots of hurdles to jump over to be able to take advantage of this tax perk. Here are some of them:

• You must have purchased the bonds after 1989 when you were at least 24 years old.
• The bonds must be in your name only.
• The bonds must be redeemed to pay for undergraduate, graduate or vocational school tuition and fees for you, your spouse, or your dependent (grandparents cannot use this tax break to help pay for their grandchild’s college tuition unless the grandparents can, on their Form 1040, claim the grandkid as a dependent).
• Room and board costs aren’t eligible for the exclusion.
• The exclusion is subject to strict income limits. For 2025, it begins to phase out at modified adjusted gross income (MAGI) of more than $149,250 for joint filers and completely phases out at MAGI of $179,250. For all other filers, the phase-out range for 2025 is $99,500 - $114,500. These figures are adjusted for inflation each year, so they would be higher for 2026 and so forth. MAGI for this purpose starts with the AGI on line 11 of your Form 1040 (figured without taking into account any I-bond interest exclusion). Then you add back any tax breaks from working abroad, the exclusion for employer-provided adoption assistance and any deductions for student loan interest.

If the proceeds from all I bonds cashed in during the year exceed the qualified education expenses that you pay for the year, the amount of I bond interest you can exclude is reduced proportionally. You would use IRS Form 8815 to compute your MAGI and the amount of any I-bond interest exclusion that you would be entitled to.

3. Medicare Premiums and IRMAA

Question: How do I calculate MAGI to determine whether I owe an income-related monthly adjustment amount (IRMAA) on top of my basic monthly Medicare Part B and D premiums? Is the untaxed portion of Social Security benefits added back in for this purpose?

Joy Taylor: True to the complexity of the federal tax code, the definition of MAGI often differs, depending on what it is used for. MAGI for purposes of determining IRMAA for Medicare purposes is your adjusted gross income shown on line 11 of your Form 1040 plus any tax-exempt interest income. As a result, the untaxed portion of your Social Security benefits is not included in MAGI.

If you'd like to learn more, here is a link to an explainer I wrote on modified adjusted gross income (MAGI).

About Ask the Editor, Tax Edition

Subscribers of The Kiplinger Tax Letter and The Kiplinger Letter can ask Joy questions about tax topics. You'll find full details of how to submit questions in The Kiplinger Tax Letter and The Kiplinger Letter. (Subscribe to The Kiplinger Tax Letter or The Kiplinger Letter.)

We have already received many questions from readers on topics related to inherited IRAs, Roth IRA conversions, responding to an IRS tax notice and more. We’ll answer some of these in a future Ask the Editor round-up. So keep those questions coming!

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