Financial advisors are supposed to look out for your best interests, but up until April, investment pros weren’t held to a “fiduciary standard,” which requires them to put their clients’ interest above everything else. The rule was passed by the Department of Labor and takes effect next year.

“It’s not as if people have been getting bad advice,” says Jean Setzfand, Financial Security VP of AARP. “But there are two different levels of responsibility, the suitability standard and the fiduciary standard.” The suitability standard allows financial advisors to recommend suitable products that match your current risk profile, but they can recommend products that come with higher fees. The fiduciary standard means that advisors need to recommend products in their clients’ best long-term interests, which means products with the lowest fees. Financial advisors who are recommending retirement products will soon be required to meet these higher-level fiduciary standards.

“If I have two products available to me and one is higher-priced and the other one is lower-priced under suitability, the advisor could recommend any product, and for their best interest they’ll recommend the higher because they get a higher commission off of it,” says Setzfand. “Under fiduciary, they have to give me the one that’s lower-cost because that’s in my best interest.”

These fees are typically hidden from consumers and can add up to a significant amount over the course of 30 years, often to hundreds of thousands of dollars.

So what can you do to make sure your financial advisor is acting in your best interests? Always ask whether they’re acting as a fiduciary while advising you on your retirement accounts. Don’t worry about offending them either. “If they tell you they’re offended, maybe you should start thinking about another advisor,” says Setzfand.

You should always ask your advisor exactly what you’re paying for. There are several layers of fees within retirement products; make sure you go through each with your advisor. Some common fees to look out for and discuss are plan administration fees, investment fees and individual service fees.