India, June 11 -- Many Americans are unaware of key workplace benefits, including 401(k) matching. Married couples in particular could be missing out on about $757 a year by not fully using these benefits.

Some couples are missing out on about $757 every year because they are not fully using their employer 401(k) matching benefits. This "missing money" is basically free cash that employers are ready to add when workers save for retirement.

Many full-time workers have a 401(k) retirement account where part of their salary is automatically saved for the future, The Sun explained. Employers often boost this savings by adding extra money, called a "match," when employees contribute to their 401(k).

There are three main types of employer ma...