This is correct. To add to this, like most things in the US 401k plans are not equally accessible to all workers. A 401k must be run through your employer so

This is correct. To add to this, like most things in the US 401k plans are not equally accessible to all workers. A 401k must be run through your employer so if your employer does not offer one your retirement savings plans will be much more difficult. There are also IRAs (Individual Retirement Accounts) which do not require an employer and work like 401ks for the most part but the contribution limit is much lower than a 401k plan ($5500 vs $18000 + employer match). If you don't have access to a 401k you'll almost certainly have to use a regular taxable brokerage account to supplement your IRA at much greater cost. Additionally, the quality of 401k plans varies from employer to employer. Some employers provide generous matches (I've heard of one that matched dollar for dollar up to the limit), most offer modest matches (up to 3% to 6% of your pre-tax pay) and some do not match at all. Some plans have very low fees (under 0.1% of assets annually) while others can have huge fees (over 1.5% of assets annually). To complicate this many HR departments (who contract for the 401k plans) do not understand how damaging high fees can be[0] and so choose 401k providers who shift the cost burden from the employer to employees (via high fees). Recent court cases have ruled that excessively high fee plans are actually illegal but it will likely take decades and many more court cases before they go away entirely. [0] https://personal.vanguard.com/us/insights/investingtruths/investing-truth-about-cost https://personal.vanguard.com/us/insights/investingtruths/in...