Short answer
A 401(k) connects retirement saving to an employer plan: employees elect to direct part of their wages into accounts under that plan. An IRA is a personal retirement savings arrangement established with a financial institution. The structural distinction is not simply pretax versus Roth—both structures can include Roth treatment. 1 2
On this page
At a glance
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| Attribute | 401(k) plan | IRA |
|---|---|---|
| Organizing structure | Employer retirement plan | Personal savings arrangement |
| Contribution mechanism described | Employee wage-deferral election | Personal contributions |
| Roth form | Plan may permit Roth deferrals | Roth IRA is a distinct type |
These comparisons reflect the supplied IRS descriptions, not every possible subtype. 1 2
What each thing is
A 401(k) is a feature of a qualified plan, with individual participant accounts inside it. An IRA is itself a personal savings arrangement; the IRS lists banks, insurance companies, and other financial institutions as places to establish one. Similar retirement purposes do not make the structures interchangeable. 1 2
Key differences
Contribution rules operate differently. A 401(k) uses elective wage deferrals, and its document may permit matching or other employer contributions. For a traditional IRA, contributions may be partly or fully deductible; Roth IRA contributions are not deductible. The excerpts do not establish current annual contribution limits for either structure. 1 2
How to tell them apart
Look for whether the account belongs to an employer’s qualified plan or is identified as an IRA established with a financial institution. A wage-deferral election under the employer plan points to a 401(k). The limit: a “Roth” label alone cannot identify the structure, because both can use Roth treatment. 1 2
Where they overlap
Both provide tax-favored retirement saving. Generally, ordinary 401(k) elective deferrals avoid current federal income taxation, while traditional IRA amounts generally are not taxed until distribution. Those similarities do not guarantee identical deductions: the IRS describes the traditional IRA contribution deduction as conditional. 1 2
Edge cases
An individual account inside a 401(k) is not an IRA merely because one employee holds the benefits. Account control also needs careful wording: employees’ elective deferrals are fully vested, but employer contributions may have service-based vesting. IRAs cannot be jointly owned; that does not establish unrestricted control over withdrawals. 1 2
Why the distinction exists
The labels identify different organizing frameworks, not just different tax results. The 401(k) framework includes employer plan documents and contribution provisions; the IRA framework centers on a personal arrangement. Within each framework, subtype matters: the IRS describes multiple 401(k) types and both traditional and Roth IRAs. 1 2
Common misconceptions
A 401(k) does not necessarily mean an employer match: matching depends on plan terms. An IRA does not necessarily mean a deductible contribution: traditional IRA deductions may be limited, and Roth contributions are nondeductible. Neither label alone supplies the complete tax treatment. 1 2
Examples
Hypothetically, an employee elects wage deferrals into an employer plan that permits matching: that is the 401(k) structure. Separately, someone establishes a Roth IRA at a bank: that is a personal IRA, with nondeductible contributions. The examples distinguish the arrangements by structure, not by whether retirement savings receive tax advantages. 1 2