High health-care costs are hitting women in the U.S. workforce much harder than men.

Working women spend $15.4 billion more in out-of-pocket health expenses annually compared to their male counterparts, according to a new analysis of employer-sponsored health plans from Deloitte Consulting.

The study found women spend 18% more than men on copays and deductibles, on average. That’s after excluding costs associated with pregnancy and maternity, according to the new report, and despite total health expenditures for women that are just 10% higher than for men.

“This is a problem we’re identifying that business leaders can actually solve within their own organizations. The takeaway being that women get paid less, and that they pay more for health care,” said Dr. Kulleni Gebreyes, U.S. chief health equity officer at Deloitte Consulting.

The result, she said, is a disproportionate financial burden.

Women tend to utilize more medical care than men, in part due to annual gynecological exams and the high costs of breast cancer imaging.

While annual exams are often fully covered, follow-ups that can result from those visits incur copays and trigger deductibles. Many of those services are often more expensive than the typical deductible, leading to a higher cost-sharing burden.    

Deloitte analysts say employers could close the $15.4 billion cost-sharing gender gap through enhanced benefits design, at an estimated cost of $133 per employee per year, or about $11 per month.

“Our ask is that companies look at their data; examine if and where the gaps exist and step back to have more of an equitable design process to come up with what are the health benefits that would meet the needs of their workforce,” said Gebreyes.