The core difference: who controls the money and when you get it

A pension is a monthly payment your employer promises to give you for life after you retire, based on how long you worked there and what you earned. A 401(k) is a savings account you control during your working years — you put money in, your employer may add some, and you decide how to invest it. When you retire, you get whatever is in that account; there is no may provide monthly check.

The pension comes from your employer's fund. The 401(k) comes from your own contributions and investment growth. This one difference shapes everything else: with a pension, your employer takes the risk that the fund will have enough money to pay you. With a 401(k), you take that risk.

Most private employers stopped offering pensions decades ago. Today, pensions are mainly found in government jobs (federal, state, local), some union positions, and a shrinking number of large corporations. If you work in the private sector, a 401(k) or similar plan is what you will encounter.

Key Takeaways

  • A pension pays you a fixed monthly amount for life; a 401(k) is a lump sum you manage yourself after you leave your job.
  • With a pension, your employer guarantees the payment and bears the investment risk; with a 401(k), you bear that risk.
  • Pensions typically require you to work for the same employer for a set number of years (often 5 to 10) before you own any of it; 401(k) contributions are usually yours immediately.
  • A 401(k) can be rolled over to another account if you change jobs; a pension stays tied to the employer who promised it.
  • Pension payments stop when you die (unless you chose a survivor option); 401(k) money passes to your heirs.

How you build up money in each plan

In a pension, you do not contribute money the way you do with a 401(k). Instead, your employer sets aside funds based on a formula — usually a percentage of your salary multiplied by your years of service. You earn a "benefit" each year you work, but you do not control where that money goes or how it is invested. The employer's finance team manages the entire fund.

In a 401(k), you choose how much to contribute from your paycheck — up to a federal limit that changes each year (in 2024, it is $23,500 for people under 50). Your employer may match a portion of what you put in, often 3 to 6 percent of your salary. You then pick from a list of investment options — usually mutual funds or target-date funds — and your money grows based on how those investments perform.

The timing of ownership differs too. With a pension, you typically own nothing until you have worked there for a set period, called vesting. This is often 5 to 10 years, though some plans vest faster. With a 401(k), your own contributions are yours immediately; your employer's match usually vests over 3 to 5 years, meaning if you leave before that time, you forfeit the unvested portion.

What you receive when you retire

A pension pays you a monthly check for the rest of your life. The amount is locked in based on your salary history and years of service. If you worked 30 years and earned an average of $60,000, your pension formula might pay you 50 percent of that average — $30,000 per year, or $2,500 per month. That payment does not change if the stock market crashes or the economy shifts.

When you retire from a 401(k), you have a lump sum — whatever you and your employer contributed plus investment gains or losses. You then decide what to do with it: leave it in the account, roll it to an IRA, take it as a lump sum (which triggers taxes), or convert it to monthly payments through an annuity. There is no may provide the money will last your whole life. If you withdraw too much early, you run out. If you withdraw too little, you leave money on the table.

Some pension plans offer a lump-sum option at retirement, letting you take all the money at once instead of monthly payments. This is rare and usually only available if the pension fund is well-funded. If you take the lump sum, you then manage it like a 401(k) — the employer's obligation ends.

Vesting: when the money becomes yours

With a pension, vesting is the key hurdle. Until you are vested, you have no claim to the employer's contributions, even if you have worked there for years. Federal law requires pensions to vest fully within 7 years, but many plans are faster — 5 years is common. Some public-sector pensions vest in 3 years or even immediately.

If you leave before vesting, you lose the employer's money entirely. If you leave after vesting, you keep the benefit you earned, but it is frozen at the salary and service level when you left. You do not earn additional years of service credit once you are gone.

A 401(k) handles vesting differently. Your contributions are always yours — vesting does not apply to your own money. Your employer's match vests on a schedule, often 20 percent per year over 5 years (called graded vesting) or 100 percent after 3 years (called cliff vesting). If you leave before the match is fully vested, you forfeit the unvested portion.

Portability: what happens when you change jobs

A 401(k) is portable. When you leave your job, you can roll it into an IRA or into your new employer's 401(k) plan. The money stays yours and continues to grow tax-deferred. You can also leave it with your old employer if the balance is above a certain amount (usually $5,000), though most people move it.

A pension is not portable in the same way. Once you are vested, your benefit is locked in with that employer. You cannot move it to a new job. If you change employers, you end up with multiple pensions — one from each employer where you vested. Each pays you based on your service and salary at that job. This is why people who change jobs frequently end up with smaller total retirement income than those who stayed at one employer.

Some public-sector pension systems allow you to transfer service credit if you move to another government job within the same system (for example, from a city job to a state job in the same state). This is rare in the private sector.

Investment risk and market exposure

With a pension, your employer bears the investment risk. If the stock market drops and the pension fund loses money, the employer must still pay you the promised amount. This is why pension funds are heavily regulated and why many employers have frozen or closed their pension plans — the liability is too large and unpredictable.

With a 401(k), you bear the investment risk. If you choose aggressive investments and the market crashes, your balance shrinks. If you choose conservative investments, your balance grows slowly. You make the choices, and you live with the results. This is why 401(k) statements always include a disclaimer that past performance does not may provide future results.

This difference matters most in a severe downturn. A pension holder's payment stays the same. A 401(k) holder who retires during a market crash may have significantly less money than expected.

Taxes and withdrawals

Pension payments are taxed as ordinary income in the year you receive them. If you receive $2,500 per month, that $30,000 per year is added to your taxable income. You do not pay taxes upfront; you pay them when the money arrives.

A 401(k) works the same way if you contributed pre-tax dollars (which most people do). When you withdraw money in retirement, it is taxed as ordinary income. If you contributed after-tax dollars (a Roth 401(k)), withdrawals are tax-free, but this is less common.

Both plans penalize early withdrawal. If you take money from a 401(k) before age 59½, you pay a 10 percent penalty plus income tax, unless you meet a narrow exception (disability, medical hardship, or a few others). Pensions typically do not allow early withdrawal at all — you must wait until your retirement date.

What happens to the money after you die

A pension stops paying when you die, unless you chose a survivor option at retirement. Common options include a reduced monthly payment that continues to your spouse for life, or a may provide that payments continue for a set number of years (like 10 years) even if you die. These options reduce your monthly check because the employer is taking on more risk.

A 401(k) passes to your heirs as part of your estate. If you named a beneficiary on the account, they receive it directly, outside probate. They then have choices: they can roll it into their own IRA, take it as a lump sum (and pay taxes), or take distributions over time. The money does not disappear when you die.

Frequently Asked Questions

Can I have both a pension and a 401(k)?

Yes. Many government employees have both — a pension from their government job and a 401(k) or similar plan (often called a 403(b) or 457 plan). Some private employers also offer both, though this is rare. If you have both, they work independently; the pension pays a fixed amount, and the 401(k) is a separate pool of money you manage.

What if my pension plan runs out of money?

The Pension Benefit Guaranty Corporation (PBGC), a federal agency, insures private-sector pensions. If your employer's pension fund fails, the PBGC takes over and pays you a benefit — though usually not the full amount you were promised. There is a maximum benefit limit that changes each year. Public-sector pensions are not insured by the PBGC; they are backed by the government entity that promised them.

Should I take a lump sum or monthly payments if my pension offers both?

This depends on your health, life expectancy, and how much you trust the employer to stay solvent. A lump sum gives you control and lets you leave money to heirs, but you must manage it and it could run out. Monthly payments may provide income for life but stop when you die. A financial advisor can help you model both scenarios based on your situation.

If I leave my job before vesting, do I lose everything?

You lose the employer's contributions to your pension. Your own contributions, if any, are always yours. With a 401(k), you lose only the unvested portion of the employer's match; your contributions and vested match stay with you. This is why it is important to check your vesting schedule before you leave a job.

Can I borrow from my 401(k) or pension?

Many 401(k) plans allow loans against your balance, usually up to 50 percent of what you have saved, with repayment over 5 years. Pensions typically do not allow loans. If you borrow from a 401(k) and leave your job before repaying, the loan is treated as a withdrawal and you owe taxes and penalties on the unpaid balance.