In reality, small businesses that offer 401(k) plans are in the minority. Only 46 percent of workers at small companies (fewer than 100 employees) are offered 401(k) plans to which employers contribute, according to the Bureau of Labor Statistics. Viewed another way, the vast majority of Americans with 401(k) plans, 77 percent, are at companies with 250 employees or more.

But small businesses are increasingly under pressure to compete with larger ones, which means they have to offer matching benefits.