Micro-captives (831(b)) and the IRS: rules, red flags and reporting

A micro-captive is a small captive insurance company, usually owned by the business it insures or by that business's owners, that elects under section 831(b) of the Internal Revenue Code to pay tax only on its investment income. For 2026 the election is available when annual premiums do not exceed $2.9 million (IRS Rev. Proc. 2025-32). The election is legal, but the IRS has treated a family of promoted structures as abusive for years, and final regulations published January 14, 2025 require disclosure of many of them. Courts have repeatedly denied the premium deductions when the "insurance" was not real.

This guide is general information, not tax advice. If you own, or are being pitched, a micro-captive, an independent CPA or tax attorney who handles captive audits should review it first.

What section 831(b) does

An ordinary insurer is taxed on its underwriting profit and investment income. Section 831(b) lets a qualifying small insurer skip tax on premium income and pay only on net investment income. To elect it, a company must meet three conditions under the statute:

• Premium limit. Net written premiums, or direct written premiums if greater, cannot exceed the annual limit. The statute started at $2.2 million and is indexed; the 2026 figure is $2,900,000.
• Diversification. Since the PATH Act of 2015, either no more than 20% of the premiums may come from any one policyholder, or the ownership of the captive must roughly match ownership of the insured businesses, with a de minimis tolerance of 2 percentage points for each "specified holder" (including lineal descendants and spouses).
• Election. The company elects the treatment, and revoking it requires IRS consent.

The business buying the coverage deducts the premium under section 162 as an ordinary expense, but only if the arrangement is insurance for tax purposes. That is the whole fight. The captive escapes tax on premium, the operating company takes a deduction, and the money is later taken out by the owners, often at lower rates than the deduction saved. The IRS focuses on structures in which that tax result is the point and insurance is the label.

What makes it insurance

Courts require risk shifting (the basics are in what is a captive insurance company and how does it work?), risk distribution and insurance in the commonly accepted sense, a framework traced to Helvering v. Le Gierse, 312 U.S. 531 (1941). Risk distribution is the usual failure. A captive that insures only three or four related businesses has too few independent exposures, so promoters added a reinsurance pool, advising that 30% of premium should come from unrelated parties. These decisions show what went wrong:

• Avrahami v. Commissioner, 149 T.C. 144 (2017): the Tax Court held that premiums paid to a captive were not insurance premiums and that the captive could not make the 831(b) election. The captive insured only a few entities, and the reinsurance pool it joined was not a bona fide insurer, citing circular fund flows, unreasonable premiums and a lack of arm's-length contracts.
• Reserve Mechanical Corp. v. Commissioner, 34 F.4th 881 (10th Cir. 2022): the Tenth Circuit affirmed a Tax Court decision against a captive arrangement that relied on a reinsurance pool.
• Syzygy Insurance Co. v. Commissioner (Tax Court, 2019) reached the same result for lack of risk distribution.
• Swift v. Commissioner, No. 24-60270 (5th Cir. July 16, 2025): the Fifth Circuit affirmed the Tax Court. A medical practice's captives and the two reinsurance pools they joined did not achieve risk distribution. The court cited circular flows of funds, the lack of arm's-length contracts and premiums that were reverse-engineered, with the pool's loss ratio at 8% against a 66% industry standard for 2015. The court noted the lack of any business need for the captives, irregular claims handling and the availability of similar commercial coverage at a fraction of the cost.

Compare these with the large single-parent cases summarized in single-parent vs group captives: which structure fits?, where captives insuring many subsidiaries with thousands of vehicles and employees succeeded. The difference is not size alone. It is whether the arrangement behaves like an insurer: independent pricing, real exposures, claims paid, and no money looped back.

The January 2025 disclosure rules

The IRS first flagged micro-captives in Notice 2016-66, which listed them as transactions of interest. A lawsuit by CIC Services reached the Supreme Court, which held in 2021 that the Anti-Injunction Act did not bar the challenge, and a district court later invalidated the notice in 2022. Treasury proposed regulations on April 11, 2023 (88 Fed. Reg. 21547), which made the notice obsolete, and issued final regulations (T.D. 10029, 90 Fed. Reg. 3534), effective January 14, 2025, adding 26 CFR 1.6011-10 and 1.6011-11. Both apply to a "captive" that has made the 831(b) election and is at least 20% owned, directly or indirectly, by the insured, its owners or related persons.

The regulations exempt certain seller's captives that insure customers' purchases, where at least 95% of the business is with unrelated customers, and employee benefit arrangements that hold a Labor Department prohibited transaction exemption.

Who has to disclose:

• Participants (the insured business, the captive, intermediaries and, with some safe harbors, owners) file Form 8886 with their returns and send a copy to the IRS Office of Tax Shelter Analysis the first time. An owner can be relieved if the insured acknowledges it will file.
• Material advisors file Form 8918. The regulations reach advisors who made a tax statement about the transaction on or after six years before January 14, 2025.
• Deadlines for earlier years. Participants with open tax years had until April 14, 2025, and material advisors until April 30, 2025. Notice 2025-24 waived the related penalties for filers who disclosed by July 31, 2025.
• Penalties. Under section 6707A, failing to disclose carries a penalty of up to $200,000 ($100,000 for a natural person) for a listed transaction and up to $50,000 ($10,000 for a natural person) for other reportable transactions, with minimums of $10,000 and $5,000. Courts have also sustained accuracy-related penalties on the understatements themselves; the Fifth Circuit upheld the 20% penalties in Swift.

The regulations are in litigation

The disclosure rules have been tested in court in 2026. In CIC Services, LLC (E.D. Tenn., March 5, 2026), the district court upheld the final regulations, and the company appealed to the Sixth Circuit. In Drake Plastics Ltd. Co. v. IRS (S.D. Tex., April 15, 2026), the court upheld the transaction-of-interest regulation but vacated the listed-transaction regulation. Both sides appealed to the Fifth Circuit, and those appeals were pending in reporting through June 2026. The transaction-of-interest rule appeared to remain in force. The status can change, so confirm it with counsel before relying on any of this.

A hypothetical worth understanding

Say a dental group pays its captive $1,000,000 a year for a package of policies it never carried before, including "pandemic business interruption" and "regulatory change" cover. The group deducts the $1,000,000, and the captive pays no tax on it. Claims are rare, and over a decade the loss ratio stays near 5%. In the ninth year the captive lends part of its reserves to a company owned by the dentist's family. This is invented to illustrate a pattern, not a real case. Under the regulations it would meet the financing factor and a loss ratio under 30%, the combination that makes a listed transaction: premium that tracks the cap, almost no claims and money looped back to the owners.

Red flags before you join

1. Tax savings lead the pitch. The brochure opens with deductions and premium caps instead of a risk you can describe.
2. Premium is set to the limit. Pricing that tracks the $2.9 million cap or your tax bill, not your exposures. The Fifth Circuit criticized "reverse-engineered" premiums.
3. New coverages at high prices. Policies for remote risks you never bought, such as terrorism, political violence or "business risk indemnity," at many times what commercial markets charge.
4. A pool that returns your premium. Reinsurance arrangements where money circles back, justified by a claim that 30% unrelated premium cures risk distribution.
5. No claims, no payouts. Loss ratios that hold near zero for years, or claims that are slow, rejected or irregular.
6. Loans back to the owners or affiliates. This is the financing factor.
7. One promoter does everything. The same group sells the program, manages the captive, picks the actuary and runs the pool.
8. Opinion letters instead of facts. A letter that promises the structure will withstand audit is not a substitute for real pricing, real underwriting and a regulator.

What a defensible small captive looks like: premiums set by an independent actuary from your actual exposures, policies you can explain to an underwriter, claims handled and paid on the policy terms, adequate capital in a regulated domicile (see Captive domiciles compared: Vermont, Utah, Delaware and offshore), no loans to insureds and a risk management reason documented in advance. Is a captive right for your business? A feasibility checklist walks through the feasibility questions.

If you already have one

1. Have independent tax counsel confirm whether you or the captive are participants in a listed transaction or transaction of interest, and whether disclosures were filed.
2. Pull the last 10 years of premiums, claims and expenses, and compute the loss ratio the way the regulations define it.
3. Identify any loans, guarantees or transfers from the captive to owners or related parties.
4. Compare each policy's price with what the commercial market charges for similar coverage.
5. Discuss with counsel whether to keep, restructure or revoke the election. The final regulations contain a limited safe harbor when a captive has revoked its 831(b) election, but consent and timing matter.

How captives are taxed more generally, including those that do not use 831(b), is covered in how captives are taxed: premiums, 831(b), excise tax and distributions. For the tax treatment of ordinary premiums, see Is business insurance tax deductible? What counts and what does not.

Key takeaways

• Section 831(b) lets a qualifying small insurer pay tax only on investment income; the 2026 premium limit is $2.9 million, and a diversification test applies.
• The tax benefit depends on the arrangement being real insurance. Courts, including the Tenth and Fifth Circuits, have denied deductions where risk distribution, pricing and claims practice fell short.
• Final regulations effective January 14, 2025 require disclosure of captives that meet a financing factor and a loss ratio under 30% (listed) or either factor, or a loss ratio under 60% (transaction of interest).
• The listed-transaction regulation was vacated by a Texas district court in April 2026, the transaction-of-interest rule was upheld, and appeals are pending, so check the current status.
• Be wary of any pitch that leads with deductions, sets premium to the cap or returns money to the owners.