(CNN) -- Women in their 40s should not get routine mammograms for early detection of breast cancer, according to updated guidelines set forth by the U.S. Preventive Services Task Force.
Before having a mammogram, women ages 40 to 49 should talk to their doctors about the risks and benefits of the test, and then decide if they want to be screened, according to the task force.
For women ages 50 to 74, it recommends routine mammography screenings every two years. Risks and benefits for women age 75 and above are unknown, it said.
The group's previous recommendation was for routine screenings every year or two for women age 40 and older.
The task force is composed of 16 health care experts, none of whom are oncologists. The group reviews medical data and bases recommendations on effectiveness and risks involved.
"All we are saying is, at age 40, a woman should make an appointment with her doctor and have a conversation about the benefits and harms of having a mammography now versus waiting to age 50," said Dr. Diana Petitti, vice chair of the task force.
While roughly 15 percent of women in their 40s detect breast cancer through mammography, many other women experience false positives, anxiety, and unnecessary biopsies as a result of the test, according to data.
But the updated guidelines don't come without controversy.
"With its new recommendations, the [task force] is essentially telling women that mammography at age 40 to 49 saves lives; just not enough of them," Dr. Otis Brawley, chief medical officer for the American Cancer Society.
The organization says it looked at virtually the same data as the task force but came to a different conclusion. "Breast cancer is a serious health problem facing adult women, and mammography is part of our solution beginning at age 40 for average-risk women," it says. It recommends annual exams beginning at that age.
Experts at the University of Texas M. D. Anderson Cancer Center also voiced concern and said they aren't changing their screening protocol. "We disagree with their conclusions," Dr. Therese Bevers said of the task force. "You have to screen more women. It's the value we put on zero women dying."
The task force acknowledged that mammograms can save lives and fear their new guidelines may be misinterpreted. "We aren't against screening women in their 40s, we just don't think it should be routine," Petitti said.
But some doctors say the language isn't clear and the confusion may turn women away from being screened at all.
Others fear insurance coverage of mammograms could be dropped based on the new recommendations.
"Certainly mammography does pick up things at [age] 45 that would have been much more serious in five years," said Dr. Anne Wallace, director of the University of California-San Diego Moores Breast Cancer Program. "What worries me is if insurance companies won't allow women who want early detection in this age group to be screened."
Susan Pisano, spokeswoman for American Health Insurance Plans, says insurance providers may revisit how they measure health plan's performance based on the updated guidelines, but adds coverage is unlikely to be dropped. "Most of our member companies look at [the task force's guidelines] as the standard. But if you are in your 40s and have a discussion about risk and benefits and your doctor gives you a referral slip, then that generally is going to be covered."
While cancer experts may not all agree with the task force's guidelines, the bottom line for women regardless of age is to discuss the pros and cons with their physician and make a screening choice based on individual needs.
Breast cancer is the most common cancer for women in the United States. This year, nearly 200,000 women will be diagnosed with invasive breast cancer, according to the American Cancer Society.
CNN.com's Elizabeth Landau contributed to this report.