US Retirement Accounts

Retirement saving in the United States relies heavily on tax-advantaged accounts — the government provides significant tax benefits to incentivise individuals to save for retirement. Understanding how each account works, how they interact, and how to maximise them is one of the highest-return personal finance decisions you can make.

The Retirement Savings Landscape

Unlike many countries, the US does not have a universal mandatory pension for private-sector workers. Instead, the system has three "legs":

1. Social Security — a federal defined-benefit program funded by payroll taxes; provides a base income in retirement
2. Employer-sponsored plans — primarily 401(k) plans; defined-contribution accounts where you and your employer contribute
3. Individual accounts — IRAs (Individual Retirement Accounts) that you open independently

401(k) Plans

A 401(k) is an employer-sponsored retirement savings plan. The name comes from the section of the Internal Revenue Code that created it (§ 401(k)).

How It Works

• Pre-tax contributions (Traditional 401k): Contributions reduce your taxable income today; withdrawals in retirement are taxed as ordinary income
• After-tax contributions (Roth 401k): Contributions come from after-tax dollars; withdrawals in retirement (including earnings) are tax-free
• Investments grow tax-deferred (Traditional) or tax-free (Roth) inside the account

2024 Contribution Limits

Category	Limit
Employee contribution limit	$23,000
Catch-up contribution (age 50+)	Additional $7,500 (total $30,500)
Total limit (employee + employer)	$69,000 (or 100% of compensation, whichever is less)

Employer Match — Free Money

Most employers match a portion of your 401(k) contributions — e.g., "50% match on the first 6% of salary":

If you earn $60,000 and contribute 6% ($3,600), your employer adds 50% of that = $1,800 free. That's an instant 50% return before any investment growth.

Always contribute at least enough to get the full employer match. Not doing so is leaving guaranteed compensation on the table.

Vesting Schedule

Employer match contributions may be subject to a vesting schedule — you don't "own" the match until you've worked there long enough:

• Cliff vesting: e.g., 0% vested until year 3, then 100% immediately
• Graded vesting: e.g., 20% per year over 5 years

Withdrawal Rules

• Normal retirement age: 59½ — withdrawals allowed without penalty
• Early withdrawal: Before 59½, you pay income tax + 10% penalty (with exceptions: disability, substantially equal periodic payments (SEPP), separation from service at age 55+, hardship)
• Required Minimum Distributions (RMDs): Must begin by age 73 (per SECURE 2.0 Act, 2022) for Traditional 401(k)s; Roth 401(k)s no longer have RMDs (as of 2024)

Individual Retirement Accounts (IRAs)

IRAs are retirement accounts you open independently at a brokerage (Fidelity, Vanguard, Schwab, etc.), regardless of your employer.

Traditional IRA

• Contributions: May be tax-deductible (depending on income and whether you have an employer plan)
• Growth: Tax-deferred
• Withdrawals: Taxed as ordinary income in retirement
• 2024 contribution limit: $7,000 ($8,000 if age 50+)
• Deductibility phase-out (if covered by workplace plan, single filer): Starts at $77,000 MAGI, fully phased out at $87,000

Roth IRA

The Roth IRA is widely considered the best retirement account available to most Americans who qualify.

• Contributions: After-tax (no deduction)
• Growth: Tax-free
• Qualified withdrawals: Completely tax-free (contributions can be withdrawn any time, earnings after age 59½ and 5-year holding period)
• No RMDs: Never required to take distributions
• 2024 contribution limit: $7,000 ($8,000 if age 50+)
• Income limits (2024): Phase-out begins at $146,000 MAGI (single) / $230,000 (married filing jointly); completely phased out at $161,000 / $240,000

Roth IRA vs. Traditional IRA — which to choose?

Situation	Better choice
You expect to be in a higher tax bracket in retirement	Roth (pay taxes now at lower rate)
You expect to be in a lower tax bracket in retirement	Traditional (defer taxes to when rate is lower)
You're young with a long time horizon	Roth (decades of tax-free compound growth)
You need to reduce taxable income now	Traditional
You're unsure	Contribute to both; diversify tax treatment

Backdoor Roth IRA

High earners above the Roth IRA income limit can use the backdoor Roth strategy:

1. Contribute to a non-deductible Traditional IRA (no income limit)
2. Immediately convert it to a Roth IRA
3. Pay taxes only on any gains (minimal if done immediately)

This is legal and widely used. Note the pro-rata rule: if you have other pre-tax IRA money, the conversion will be partially taxable proportional to pre-tax funds.

Self-Employed Retirement Accounts

Account	2024 Limit	Best for
SEP-IRA	25% of net self-employment income, up to $69,000	Simple; ideal for sole proprietors
Solo 401(k)	$23,000 employee + up to $46,000 employer = $69,000 total	Higher limits; good for high-income self-employed
SIMPLE IRA	$16,000 ($19,500 catch-up)	Small businesses with employees

Social Security

Social Security (administered by the Social Security Administration, SSA) is a federal program that provides retirement, disability, and survivor benefits. It is funded by payroll taxes — 6.2% from employee + 6.2% from employer on wages up to the Social Security wage base ($168,600 in 2024). Self-employed pay both sides (12.4% total, but deduct half).

Eligibility

• You need 40 work credits (roughly 10 years of work) to qualify for retirement benefits
• Credits are earned by earning income — up to 4 credits per year

Benefit Calculation

Your benefit is based on your 35 highest-earning years of indexed wages (called the AIME — Average Indexed Monthly Earnings). The SSA then applies a progressive formula (the PIA — Primary Insurance Amount) to calculate your monthly benefit.

When to Claim

Age	Effect on benefit
62	Earliest you can claim; benefit reduced by up to 30% permanently
67 (born 1960+)	Full Retirement Age (FRA) — 100% of PIA
70	Maximum benefit — 8% higher per year than FRA for each year you delay

Break-even analysis: Claiming at 70 vs. 62 takes roughly 12–13 years of higher payments to recoup the missed early payments. If you expect to live past ~80, delaying often pays off significantly.

Social Security and Taxes

Up to 85% of Social Security benefits can be subject to federal income tax if your "combined income" (AGI + non-taxable interest + half of Social Security) exceeds:

• $25,000 (single) / $32,000 (married filing jointly) — up to 50% taxable
• $34,000 (single) / $44,000 (married) — up to 85% taxable

The Recommended Priority Order

Most personal finance experts recommend this general priority for retirement saving:

1. 401(k) up to employer match — guaranteed return via match
2. Pay off high-interest debt (credit cards > ~6%)
3. Max out HSA (if eligible — triple tax advantage for healthcare)
4. Max out Roth IRA ($7,000)
5. Max out 401(k) (remaining $16,000 to reach $23,000 limit)
6. Taxable brokerage account — for additional investing beyond tax-advantaged space

Key Terms Reference

Term	Definition
MAGI	Modified Adjusted Gross Income — AGI with certain deductions added back
RMD	Required Minimum Distribution — mandatory withdrawals starting at age 73
Vesting	Ownership of employer contributions per the plan schedule
Rollover	Moving money from one retirement account to another without tax consequences
Direct rollover	Funds go directly from old plan to new — preferred (no withholding)
60-day rollover	You receive the funds and must redeposit within 60 days — risky

Study Snapshot

US Retirement Accounts covers 401(k), Traditional IRA, Roth IRA, Social Security, contribution limits, withdrawal rules, and optimal saving strategies.

Concept Flow

Check Your Understanding

1. Why should you always contribute at least enough to get the full 401(k) employer match?
2. What is the difference in tax treatment between a Traditional IRA and a Roth IRA?
3. What is the penalty for withdrawing from a 401(k) before age 59½?
4. At what age does Social Security reach its maximum monthly benefit?

What to Review Next

• HSA (Health Savings Account) — the "triple tax advantage"
• Asset allocation and investment selection within 401(k)/IRA
• Roth conversion strategy (converting Traditional to Roth in low-income years)