The IRS Just Added a New Scam to Its 'Dirty Dozen' List. CPAs Need to Watch For This.

The IRS just released its annual Dirty Dozen list of tax scams for 2026. And there's a new one on the list that CPAs need to watch for. Form 2439 fraud is now #6 on the IRS's hit list—replacing fuel tax credit scams that dominated prior years. That's a big shift. And it means the IRS is seeing enough abusive claims tied to undistributed long-term capital gains that it made the top 12. If you have clients with investment funds or REITs, here's what you need to know.

What Is Form 2439?

Form 2439, Notice to Shareholder of Undistributed Long-Term Capital Gains, allows shareholders of certain regulated investment companies (RICs) or real estate investment trusts (REITs) to claim a refundable credit for taxes paid on undistributed capital gains. In plain English: if the fund made capital gains but didn't distribute them to you, the fund paid tax on those gains at the corporate level. Form 2439 lets you claim credit for your share of that tax. It's a legitimate form—when used correctly.

The Scam

The IRS is seeing two main fraud patterns: 1. **Overstated claims.** Taxpayers inflate the amount of undistributed gains or fabricate the credit entirely. The numbers don't match what the fund actually paid. 2. **Fake organizations.** Scammers claim credits tied to organizations that aren't legitimate investment funds or REITs—or worse, falsely link claims to real, well-known organizations that never issued a Form 2439. Both schemes lead to the same outcome: a massive refund based on phantom tax credits. And because Form 2439 is relatively obscure, a lot of tax preparers don't know what a legitimate claim looks like. That makes it easy for scammers to slip fraudulent returns past preparers who assume the form is legit.

Why This Made the Dirty Dozen

The Dirty Dozen isn't random. The IRS picks scams that are actively spiking—threats it's seeing in volume right now. Form 2439 fraud replacing fuel tax credit scams signals a major shift. Fuel tax credits dominated the list for years because scammers filed thousands of bogus claims. The IRS shut that down hard. Now they've moved to Form 2439. And the IRS is flagging it publicly because it's working—scammers are getting refunds, and the volume is rising fast enough to crack the top 12.

What CPAs Should Watch For

If a client comes to you with Form 2439, here's your due diligence checklist: 1. **Verify the organization.** Is it a real RIC or REIT? Use the IRS's [tax-exempt organization search tool](https://www.irs.gov/charities-non-profits/search-for-tax-exempt-organizations) to confirm. 2. **Check the numbers.** Does the form match the fund's actual distribution records? Call the fund if you need to verify. 3. **Look for red flags.** Did the client get this form from a "tax credit promoter" or social media group? That's a massive warning sign. 4. **Ask where it came from.** Legitimate Form 2439s come directly from the fund or REIT—not from a third party offering to "help you claim tax credits you're owed." 5. **Know the consequences.** Improper Form 2439 claims will trigger audits, penalties, and potential enforcement action. The IRS explicitly warned that it's scrutinizing these claims.

The Other 11 Scams on the List

Form 2439 is new, but the rest of the Dirty Dozen includes familiar threats: • **IRS impersonation (phishing/smishing)** — Over 600 social media impersonators reported in FY 2025 • **AI-enabled robocalls** — Spoofed caller IDs using voice mimicry • **Fake charities** — Exploiting disasters to collect donations and data • **Social media tax hacks** — Viral "tax tips" that lead to audits and penalties • **IRS Online Account identity theft** — Criminals hijacking online accounts • **Bogus "Self-Employment Tax Credit"** — Misleading promotions for credits that don't exist • **Ghost preparers** — Preparers who won't sign returns or provide a PTIN • **Non-cash charitable schemes** — Inflated appraisals of donated property • **Overstated withholding** — Fabricated W-2/1099 data to manufacture refunds • **Spear-phishing tax pros** — "New client" emails delivering malware • **OIC mills** — High-pressure Offer in Compromise marketing targeting people who don't qualify

National Slam the Scam Day

The IRS timed this year's Dirty Dozen release with National Slam the Scam Day on March 5. The message is clear: scammers are evolving, and taxpayers need to stay ahead. IRS CEO Frank J. Bisignano put it simply: "Thieves continuously adjust the pitches they use to take advantage of honest taxpayers." For CPAs, that means staying vigilant—especially during filing season when scammers ramp up.

The Bottom Line

Form 2439 fraud is now a top-tier IRS enforcement priority. If you see one on a client's return, verify it before filing. The IRS is watching these claims closely, and improper filings will trigger audits, penalties, or worse. And if a client tells you they heard about this "tax credit" on TikTok? That's your cue to run the other direction.