The incidental benefit rule for retirement plans is the tax-code principle that any non-retirement feature inside a qualified plan — life insurance, retiree medical coverage, or survivor payouts — must stay smaller than the retirement benefit itself. If those extras grow too large relative to the retirement savings, the plan can lose its tax-advantaged status. The rule shows up in several places across the Internal Revenue Code and IRS guidance, each with its own percentage test or formula.
Where the Rule Comes From
The rule flows from a foundational requirement in Section 401(a): a qualified plan trust must exist for the “exclusive benefit” of employees and their beneficiaries. Contributions have to go toward distributing the fund’s accumulated corpus and income to participants, and no part of the trust can be diverted to other purposes before liabilities to employees and beneficiaries are satisfied.1Office of the Law Revision Counsel. 26 USC 401 – Qualified Pension, Profit-Sharing, and Stock Bonus Plans
Exclusive benefit doesn’t mean the plan can only pay retirement checks. Life insurance, disability coverage, and retiree medical accounts can all fit within a qualified plan, so long as they stay subordinate. When ancillary benefits start consuming a disproportionate share of contributions, the plan stops looking like a retirement vehicle and starts looking like a tax-sheltered insurance arrangement, which is what the IRS won’t accept.
Life Insurance Limits Inside a Qualified Plan
Life insurance is the most common ancillary benefit inside qualified plans, and the IRS has drawn bright-line tests to keep it in check. The tests differ between defined contribution and defined benefit plans.
Percentage Tests for Defined Contribution Plans
For 401(k)s, profit-sharing plans, and other defined contribution plans, the IRS measures life insurance premiums against total contributions to the participant’s account:
- Whole life premiums cannot exceed 50% of cumulative employer contributions allocated to the participant’s account. The higher threshold reflects the cash value whole life builds, which eventually contributes to the retirement benefit.
- Term or universal life premiums cannot exceed 25% of cumulative employer contributions.
- For combination policies, half the whole life premiums plus all term premiums cannot exceed 25% of contributions.
Profit-sharing plans get a specific carve-out. If employer contributions have been held in the plan for at least two years before being used to buy insurance, no percentage limit applies. Money seasoned for two years has already shown its retirement-savings purpose.
The 100-to-1 Ratio for Defined Benefit Plans
Defined benefit plans use a different yardstick. Under Revenue Ruling 74-307, the death benefit from life insurance cannot exceed 100 times the participant’s projected monthly pension benefit. A participant expected to receive $2,500 per month at retirement can have a maximum death benefit of $250,000 through plan-held life insurance. This ratio works alongside the percentage tests. A plan that passes one but fails the other still has a problem.
Retiree Medical Benefits Under Section 401(h)
Pension and annuity plans can set up a separate account under Section 401(h) to pay medical expenses for retired employees, their spouses, and dependents. The account gets favorable tax treatment, but the incidental benefit rule imposes tight conditions: the medical benefits must be subordinate to retirement benefits, contributions to the medical account must be reasonable and separately tracked, and any money left after all medical liabilities are satisfied must revert to the employer.2Office of the Law Revision Counsel. 26 U.S. Code 401 – Qualified Pension, Profit-Sharing, and Stock Bonus Plans
Subordination comes with a hard cap. Aggregate contributions for medical benefits, combined with contributions for life insurance protection, cannot exceed 25% of total actual contributions to the plan (excluding contributions that fund past service credits).3Internal Revenue Service. Chapter 8 IRC Section 401(h) Retiree Medical Benefits Medical and insurance benefits share a single budget inside the plan. A plan that spends 20% of contributions on life insurance has only 5% left for retiree medical before hitting the wall.
The Rule on Non-Spouse Survivor Payouts
The incidental benefit rule also shapes how retirement benefits can be distributed when a participant names a beneficiary much younger than themselves. The Minimum Distribution Incidental Benefit (MDIB) requirement in Treasury Regulation Section 1.401(a)(9)-6(b) prevents participants from structuring payouts so that most of the money flows to heirs instead of supporting the participant during retirement.4eCFR. 26 CFR 1.401(a)(9)-6 – Required Minimum Distributions for Defined Benefit Plans and Annuity Contracts
MDIB is automatically satisfied in two common situations: a life annuity for the participant’s own life only, and a joint and survivor annuity with a spouse as sole beneficiary, regardless of the age gap. The rules get restrictive when a non-spouse beneficiary is involved. The survivor’s annuity payment cannot exceed a percentage of the participant’s payment, and that percentage shrinks as the age gap widens.
If the beneficiary is 10 years younger or less, the survivor can receive up to 100% of the participant’s annuity. At a 15-year gap, the survivor payment drops to 84%. At 20 years, 73%. At 25 years, 66%. The regulation includes a full table running the percentages down for each year of age difference.4eCFR. 26 CFR 1.401(a)(9)-6 – Required Minimum Distributions for Defined Benefit Plans and Annuity Contracts A 70-year-old retiree who names a 40-year-old child as survivor beneficiary faces a meaningful reduction in what the child can inherit through the annuity stream.
The Annual Tax Cost of Insurance Inside the Plan
Holding life insurance inside a qualified plan creates an annual tax event that catches some participants off guard. Even though no cash has come out of the plan, the cost of the life insurance protection you receive each year counts as taxable income. The plan trustee reports the amount on Form 1099-R using distribution code 9, and you owe income tax on it for that year.5Internal Revenue Service. Instructions for Forms 1099-R and 5498 (2025)
The taxable amount is determined using IRS Table 2001, which replaced the older P.S. 58 rate tables under Notice 2001-10.6Internal Revenue Service. Notice 2001-10 – Split-Dollar Life Insurance Arrangements An insurer’s published one-year term rates can be used instead if they are lower than Table 2001 rates and available to all standard risks. There is a silver lining. The cumulative amount you’ve been taxed on over the years — your basis in the policy — reduces the taxable amount when the policy is eventually distributed or the death benefit is paid. The same dollars don’t get taxed twice.
What Happens to the Policy When You Retire
A life insurance policy cannot stay inside a qualified plan indefinitely. When you retire or otherwise separate from service, the plan has to deal with it. The common outcomes:
- Distribution to the participant. If the plan distributes the policy to you, the cash value at the time of distribution is taxable as ordinary income, minus any basis from Table 2001 costs you’ve already been taxed on.
- Conversion to an annuity. Within 60 days of distribution, you can convert the policy into a contract with no life insurance protection, avoiding immediate taxation. The converted contract must be nontransferable and stripped of any death benefit excludable from income under the life insurance proceeds rules.
- Surrender by the plan. The trustee can surrender the policy and add the cash value back to your plan account, where it becomes part of your retirement benefit pool.
The conversion option is where people trip up most often. The 60-day window is strict. Miss the deadline or skip the conversion, and you face an immediate tax bill on the full cash value.
What Happens If the Rule Is Broken
The stakes reach past the individual participant. When a qualified plan is disqualified, the trust loses its tax-exempt status entirely, and the consequences hit everyone involved.7Internal Revenue Service. Tax Consequences of Plan Disqualification
For participants, the impact depends on classification. If the disqualification stems from coverage or participation failures and you’re highly compensated, your entire vested account balance becomes taxable income, not just the contributions from the disqualified years. Rank-and-file employees generally face a lighter hit, with only employer contributions from the disqualified years included in income to the extent they’re vested.
The employer takes a hit too. Contributions to a disqualified plan’s trust can no longer be deducted in the year they’re made; the deduction is delayed until the contribution is actually included in the employee’s gross income. For defined benefit plans that don’t maintain separate accounts, the employer may lose the deduction entirely. The trust itself must start filing Form 1041 and paying income tax on its investment earnings, which had previously grown tax-free.7Internal Revenue Service. Tax Consequences of Plan Disqualification
The IRS would rather see a plan fixed than destroyed. Minor operational failures can be handled under the Self-Correction Program without filing anything or paying a fee, provided the error qualifies as insignificant based on factors like the percentage of assets involved, the number of participants affected, and how promptly the sponsor corrected after discovery.8Internal Revenue Service. 9Internal Revenue Service. Voluntary Correction Program (VCP) Fees If the IRS finds the violation first during an audit, correction happens through the Audit Closing Agreement Program, with negotiated sanctions that are typically larger than VCP fees but still cheaper than disqualification. The sooner a violation is identified, the cheaper the fix.