Your First 401(k)

The 401(k) enrollment packet is the highest-paid paperwork of your twenties. Three decisions — contribution, Roth-or-Traditional, investment — and you can beat most adults’ retirement setup in fifteen minutes.

Decision 1: How Much Should I Contribute?

At minimum: whatever captures the full employer match. A typical “100% of the first 4%” match is a guaranteed, instant doubling of your money — skipping it is declining part of your salary. Beyond the match, follow the Order of Operations: starter emergency fund and high-interest debt first, then come back and climb toward the $24,500 limit (2026) as income grows.[1] The painless mechanism: raise your percentage by 1–2 points every raise, before the raise reaches your checking account — and check whether your plan’s auto-escalation will do it for you. Most employers now will automatically have your 401(k) increase 1% per year unless you tell them not to do it.

Decision 2: Roth 401(k) or Traditional?

Same question as every tax choice: pay tax now or later — whichever era is cheaper. In your twenties, with decades of raises presumably ahead, Roth usually wins: contribute after-tax at today’s low bracket and never pay tax on the growth. Traditional wins in peak-earning years or high-tax states with retirement moves planned.

One useful wrinkle: even if you send your contributions to the Roth side, the employer match has traditionally landed pre-tax in the plan’s traditional bucket. That means choosing Roth still leaves you with money in both, which is tax diversification you get without deciding anything. (SECURE 2.0 now lets plans offer a Roth match if you elect it — taxable to you in the year it is made — so check which way yours is set up.)

Unsure? Splitting is a legitimate hedge — for every percentage above the employer match. Just be aware of how your employer’s plan allows to break up the percentages. Some will allow fractions of a percent while others will require whole percentages only. The fuller framework is in Tax Strategies. A Roth IRA on top — step 6 of the Order — adds another $7,500 of room with more investment choices.

Decision 3: What Do I Invest In?

The enrollment menu is where new savers freeze. Two clean answers: a target-date fund for roughly your 65th-birthday year (one fund, auto-rebalancing, done), or a low-cost index fund combo if the plan’s target-date fees are high — compare expense ratios; under ~0.20% is good.

What matters most: do not leave contributions in the cash/stable-value default! This quietly happens to millions of new enrollees. The why behind index funds lives in Investing Basics and Investing for Retirement.