401(h) vs 401(a): Code Sections, Vehicles, and What Each Actually Covers

Section 401(a) of the Internal Revenue Code is the bedrock upon which most qualified retirement plans are built. This comprehensive section outlines the stringent requirements a plan must satisfy to receive preferential tax treatment. These rules cover a vast array of operational aspects, from who can be covered by the plan to how benefits vest and are funded, and ultimately, how those benefits are distributed to participants.

Nearly every employer-sponsored retirement plan, whether a traditional defined benefit pension, a money purchase plan, or a profit-sharing plan, must comply with the qualification rules of Section 401(a). Adhering to these rules allows employers to deduct contributions made to the plan, and allows plan assets to grow tax-deferred until distribution. Participants benefit from tax-deferred growth on their account balances.

In contrast to the broad scope of 401(a), Section 401(h) is a unique and highly specialized provision. It permits certain qualified plans to establish a separate sub-account specifically for the purpose of paying retiree medical benefits. This means a 401(h) account can never exist as a standalone retirement vehicle; it must always be an integrated feature within an underlying 401(a) plan.

Crucially, only qualified pension or annuity plans are eligible to host a 401(h) sub-account. Profit-sharing plans or 401(k) plans, despite being 401(a) plans, do not qualify for this specific benefit. The 401(h) account acts as an additional layer, explicitly designed to help employers pre-fund the often substantial costs of healthcare for their retired employees. Funds within this account are shielded from taxes as they grow and are disbursed.

When financial advisors or plan administrators discuss a "401(a) plan with a 401(h) account," they are referring to a qualified retirement plan—specifically, a pension or annuity plan—that has incorporated this specialized retiree medical sub-account. The crucial aspect here is the integrated architecture: the 401(h) account is entirely dependent on the existence and ongoing qualification of its underlying 401(a) plan.

This structural dependency has significant practical implications. Any question regarding the compliance, funding, or operation of the 401(h) account must first trace back to the rules governing the parent 401(a) plan. If the underlying 401(a) plan fails to meet its qualification requirements, the tax-advantaged status of the 401(h) account could also be jeopardized. Understanding this relationship is key to proper plan design and administration.

The fundamental distinction between 401(a) and 401(h) lies in their core objectives. Section 401(a) broadly enables the creation of qualified plans primarily for retirement income deferral and accumulation. Its purpose is to provide a framework for employers to offer employees a way to save for retirement on a tax-advantaged basis.

Conversely, 401(h) has a singular, dedicated purpose: to fund health benefits for retirees. It's not about income replacement in retirement, but rather about addressing the escalating costs of medical care in post-employment years. This specialized function means that funds contributed to a 401(h) account can only be used for eligible medical expenses, unlike general 401(a) plan assets which are typically distributed as cash or annuities for any purpose in retirement.

Both 401(a) plans and 401(h) accounts offer significant tax advantages, but they operate under separate contribution rules. Contributions to the main 401(a) plan, whether by employer or employee, are subject to various IRS limits depending on the plan type. These contributions are generally tax-deductible for the employer and grow tax-deferred for participants.

For a 401(h) sub-account, there's a specific, crucial limitation: contributions for medical benefits cannot exceed 25% of the employer's total contributions to the underlying pension or annuity plan (excluding prior health contributions) since the 401(h) account was established. This