Watch 401(k) contribution limits.

The limitations are per employee—not per account. The IRS is about to enforce excess contributions.

Be aware: some employees exceed the annual limit ($19,000 for 2019) because they have multiple accounts, according to a Treasury report.

Popular cause of excess contributions:

An employee who changes jobs during the year or has more than one job schedules contributions up to the annual maximum with each employer. But the annual limit applies to the total contributions made to all accounts.

IRS red flag: Those who have more than one 401(k) account during the year. [Tax Notes Today]