Derek Bonnar, Canstar's general manager NZ, said KiwiSavers should take time to look closely at those statements to see if they are getting a good deal.
"Fees can end up costing thousands of dollars over the life of an investment and disclosing them in an open way will mean more transparency for the saver," he said.
"I encourage all KiwiSaver investors to have a look at the total expense ratio of their fund and compare it with other products on the market."
The 'total expense ratio' is a measure of the total cost of a fund to the investor.
According to Canstar's analysis, the average total annual fee on a KiwiSaver balance of $7,500 was $101.59, but fees varied significantly between providers.
Bonnar said while investors couldn't control their investment returns, they could control the amount of fees they paid.
Meanwhile, Canstar's star ratings report found ASB offered the best value for KiwiSavers.
ASB was awarded a five-star rating in each of the three risk profiles - conservative, balanced and growth.
The star ratings are not based on performance but on fees and other features, such as the range of investment options, level of communication, availability of advice, and ease of account access.
"ASB are to be congratulated for achieving a five-star rating in each of the assessed profiles for the third year in a row," Bonnar said.
Canstar said ASB absorbed its trustee and expense fees into one simple management fee and that members could easily apply online, and check their balance through a mobile app.
ASB also offered educational material through its website and on YouTube.
Private company SuperLife Limited also achieved five stars in the balanced and growth profiles for the third year running.
BNZ, Tower and Medical Assurance Society were also awarded five-star ratings for outstanding value in various profiles.
KiwiSaver was launched in 2007 and how has 2.16 million members.
