What is the $100,000 loophole for family loans?

The $100,000 loophole is the IRC Section 7872 exception that lets family loans of $100,000 or less avoid or reduce imputed interest income for the lender, but it does not exempt the loan from gift tax rules entirely.

Under this provision, if the total outstanding loans between a lender and borrower never exceed $100,000, the imputed interest the lender must report as income is capped by the borrower's net investment income for the year, and it drops to zero if that income is $1,000 or less. Without this exception, the IRS would treat a below-market or interest-free family loan as if the lender charged the applicable federal rate (AFR) and then gifted the difference back to the borrower, creating both imputed interest income and a taxable gift.

It is important to understand what the loophole does not do. It only limits the income tax consequences (the imputed interest the lender reports), not the gift tax treatment of the foregone interest. That foregone interest is still technically a transfer of value from lender to borrower. In practice, because AFRs are often modest, the imputed gift on a loan capped at $100,000 tends to fall within the annual gift tax exclusion, so it rarely triggers a tax bill or even a filing requirement. Larger family loans, or loans that push imputed interest above the exclusion, may still require gift tax valuation to document the value of the transfer accurately for Form 709 purposes.

Because the interaction between loan structuring, imputed interest, and gift tax exclusions can get complicated, families making sizable loans often benefit from a professional valuation to confirm reporting is accurate. For more on how transfers like these are valued, see our answer on how gifts are valued for tax purposes.