Individual 401(k)s allow for contributions of up to $19,500 in 2020 and 2021 from individuals and additional catch-up contributions of $6,500. Businesses can contribute up to 25% of compensation not exceeding $57,000 in 2020 and $58,000 in 2021. Contributions are tax deductible for businesses and investment gains and elective contributions can be tax deferred until distribution. Individual 401(k)s offer pre-tax and Roth options but may require annual tax filings and are exempt from discrimination testing as they have no employees.