The Section 1291 PFIC rules are the default U.S. tax regime for anyone who holds shares in a passive foreign investment company without making a timely election to opt out. If a distribution from the fund is unusually large, or if you sell the shares at a gain, the tax code treats the excess as if it had accrued evenly across every day you owned the stock, taxes each prior year’s slice at that year’s top individual rate, and adds daily compounding interest running from the original due date of each of those old returns. The math almost always produces a bill larger than you would have owed on a comparable domestic investment, and most people caught by it never knew their foreign mutual fund or ETF was a PFIC.
What Makes a Foreign Corporation a PFIC
A foreign corporation is a PFIC for a tax year if it meets either of two tests. The income test looks at whether 75% or more of gross income for the year is passive. The asset test looks at whether at least 50% of assets, measured by average value over the year, produce or are held to produce passive income. One test is enough.1Office of the Law Revision Counsel. 26 U.S. Code 1297 – Passive Foreign Investment Company
Passive income here borrows the foreign personal holding company definition: interest, dividends, royalties, rents, annuities, net gains from selling property that throws off those items, and foreign currency gains outside an active business. Narrow carve-outs exist for active banking and insurance operations, but they rarely help an individual investor.1Office of the Law Revision Counsel. 26 U.S. Code 1297 – Passive Foreign Investment Company
The investments most likely to qualify are pooled vehicles incorporated outside the United States: foreign mutual funds, foreign ETFs, foreign closed-end funds, offshore hedge funds, offshore insurance products with investment components, and money-market funds inside overseas bank accounts. Some non-U.S. pension plans fall under the definition, which surprises many Americans living abroad. A foreign holding company whose main asset is a stock portfolio can trip the asset test on its own. None of these show up on a brokerage statement with any warning label; the burden of identifying them sits entirely on you.
How the Excess Distribution Is Calculated
The excess distribution is what triggers Section 1291’s punitive machinery. You compare the current year’s distribution to 125% of your average annual distributions over the prior three years (or over your entire holding period if it is shorter). Anything above 125% of that average is the excess.2Office of the Law Revision Counsel. 26 USC 1291 – Interest on Tax Deferral
A concrete example: suppose you received $800, $1,000, and $1,200 from the fund over the last three years. The three-year average is $1,000. Multiply by 125% and the threshold is $1,250. A $2,000 distribution this year produces a $750 excess. The first $1,250 is taxed as ordinary income under normal rules. The $750 goes through the allocation-and-interest formula below.
If you received nothing in the prior three years, the entire current-year distribution is excess. The one relief valve is that no excess distribution exists for the very first year of your holding period.2Office of the Law Revision Counsel. 26 USC 1291 – Interest on Tax Deferral
Selling the Shares Gets the Same Treatment
You cannot sidestep Section 1291 by holding the stock and cashing out later. Any gain you recognize on selling or otherwise disposing of PFIC shares is treated as if it were an excess distribution and run through the same formula.2Office of the Law Revision Counsel. 26 USC 1291 – Interest on Tax Deferral A longer holding period actually makes the outcome worse, because the gain gets spread across more years of compounding interest.
How the Tax and Interest Are Computed
Once you have identified the excess distribution or the gain on sale, you spread the amount ratably across every day of your holding period. Each year gets its proportional slice.
The slice allocated to the current tax year, and any slice allocated to years before the corporation first became a PFIC, gets added to ordinary income for the current year and taxed at your actual rate. Everything else, meaning every slice allocated to a prior year during which the entity was a PFIC, is taxed at the highest individual rate that was in effect for that year. Your actual bracket in those years is irrelevant; you pay the top rate on every allocated slice. For 2026, that top rate is 37%.3Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
A daily compounding interest charge then accrues on each year’s deferred tax. The rate is the IRS underpayment rate, equal to the federal short-term rate plus three percentage points.4Office of the Law Revision Counsel. 26 U.S. Code 6621 – Determination of Rate of Interest It sits at 7% for the first quarter of 2026 and 6% for the second.5Internal Revenue Service. Quarterly Interest Rates Interest runs from the original due date of the return for each allocated year through the current year’s filing date. Top-bracket taxation plus years of compounding is what makes the regime bite.
Two Rules That Trap Long-Term Holders
Two features of the regime catch investors who assume they can wait the problem out.
The first is the “once a PFIC, always a PFIC” rule. Once a foreign corporation qualifies as a PFIC during a year you own its stock, it remains a PFIC as to your shares for every future year, even if the company later fails both tests. The taint follows the shares in your hands. The only cure is a purging election.6eCFR. 26 CFR 1.1297-3 – Deemed Sale or Deemed Dividend Election
The second is the loss of the basis step-up at death. Most inherited assets get their basis reset to fair market value on the date of death, wiping out unrealized gain. PFIC shares held by a U.S. decedent do not. The heir’s basis is reduced by the amount of the built-in gain, so in practice the heir inherits the decedent’s adjusted basis rather than the fair market value. The one exception is a decedent who was a nonresident alien for the entire holding period; in that case, the normal step-up applies.7Office of the Law Revision Counsel. 26 U.S. Code 1291 – Interest on Tax Deferral Holding until death does not defuse Section 1291; it just hands the bill to the next generation.
How to Avoid Section 1291
The whole regime is a default. Two elections let you opt out, and both produce dramatically better outcomes than doing nothing. Making one in the first year you own the stock is the single most valuable move available.
Qualified Electing Fund Election
A QEF election requires you to include your pro rata share of the fund’s ordinary earnings and net capital gains in income each year, whether or not the fund actually distributes anything. Ordinary earnings are taxed as ordinary income; the capital gain portion keeps its favorable long-term capital gains rate.8Internal Revenue Service. Instructions for Form 8621 Once made, the election applies to every future year unless the IRS consents to revocation.9Office of the Law Revision Counsel. 26 U.S. Code 1295 – Qualified Electing Fund
The catch is practical. The PFIC has to give you an annual information statement breaking out its ordinary earnings and net capital gains, and most foreign funds marketed to non-U.S. investors simply do not produce one. Without that statement, a QEF election is not feasible. The election is due by the return’s due date, including extensions, and getting relief for a late one is difficult.9Office of the Law Revision Counsel. 26 U.S. Code 1295 – Qualified Electing Fund
Mark-to-Market Election
If the PFIC stock is “marketable,” meaning it is regularly traded on a national securities exchange registered with the SEC or a foreign exchange the IRS has approved, you can elect mark-to-market treatment under Section 1296. Each year you recognize ordinary income equal to any increase in fair market value over adjusted basis. If value drops, you can deduct the loss, but only up to the total of gains you previously included under the election.10Office of the Law Revision Counsel. 26 USC 1296 – Election of Mark to Market for Marketable Stock
Both gains and losses under the election are ordinary rather than capital, so you give up the lower capital gains rate. In exchange, you avoid the top-bracket taxation and compounding interest of the Section 1291 default. For most holders of publicly traded foreign funds, the mark-to-market election is the simpler path, because it does not depend on the fund producing anything for you.
Purging Elections If You Started Late
If you already own PFIC stock and did not make a QEF or mark-to-market election in year one, you cannot just start one going forward. You first have to clear the Section 1291 taint through a purging election. You pick either a deemed sale (you pretend to sell at fair market value and pay the full Section 1291 tax and interest on that hypothetical gain) or a deemed dividend (you treat the unrealized gain as an excess distribution). After paying the resulting tax, the taint is gone and the QEF or mark-to-market election takes effect prospectively.6eCFR. 26 CFR 1.1297-3 – Deemed Sale or Deemed Dividend Election It is expensive, but it stops interest from continuing to compound, and waiting only makes the eventual purge cost more.
Reporting on Form 8621
Form 8621 is the reporting vehicle for everything above. File a separate form for each PFIC you hold, directly or indirectly through a chain of foreign entities.11Internal Revenue Service. Instructions for Form 8621 Before you start, gather the purchase date and cost basis for the shares and a full history of every distribution you have received; without that, the 125% average calculation is not possible. The Section 1291 computation, including the allocation across your holding period and the deferred tax and interest, goes in Part V of the form.8Internal Revenue Service. Instructions for Form 8621 Attach the form to your Form 1040 and file by the return’s due date, including extensions; the additional tax and interest flow onto Schedule 2 of the 1040.
De Minimis Exception
Not every PFIC shareholder files every year. If the total value of all directly held PFIC stock is $25,000 or less on the last day of the tax year ($50,000 for joint filers), and you received no excess distribution and recognized no gain on selling PFIC stock during the year, you are exempt from filing.11Internal Revenue Service. Instructions for Form 8621 For PFICs owned indirectly through another PFIC, the threshold drops to $5,000. The exemption disappears the moment you receive an excess distribution or sell at a gain, regardless of the portfolio’s value.
What Happens If You Do Not File
Missing a required Form 8621 does not trigger a standalone dollar penalty the way missing an FBAR or Form 8938 would. The consequence is arguably worse: the statute of limitations on the entire tax return stays open. Normally the IRS has three years after you file to assess additional tax. With a missing Form 8621, the assessment clock does not start until three years after you finally provide the missing information.12Office of the Law Revision Counsel. 26 U.S. Code 6501 – Limitations on Assessment and Collection
Every item on that return, not just the PFIC items, remains open to audit with no expiration date. If the omission was due to reasonable cause rather than willful neglect, the open period narrows to just the PFIC-related items.12Office of the Law Revision Counsel. 26 U.S. Code 6501 – Limitations on Assessment and Collection Reasonable cause is hard to prove after the fact, and the IRS has broad discretion.
Because the assessment period can stay open indefinitely, keep every record tied to your PFIC holdings, including purchase confirmations, distribution history, and copies of each Form 8621, for as long as you own the investment and for at least three years after filing the final return that includes the last required Form 8621. The usual three- and six-year retention periods are not enough here.