Retailers and apparel brands should target more than just millennials, according to a new study by consulting firm A.T. Kearney and market research company The NPD Group. Though millennials surpass other generations in volume of purchases, the 18- to 34-year-old crowd makes up only 38% of total spending on apparel in the United States, the “Age Isn’t Everything” report notes.

“Everyone’s talking about millennials now, but there’s a real risk in ignoring other generations who still wield tremendous purchasing power,” says Marshal Cohen, chief industry analyst for NPD. “And, when it comes to millennials, the other thing many retailers fail to understand is that not all millennials are created equal. Depending on lifestyle and life stage, millennials could be more – or less – likely to buy your brand.”

Millennials dominate purchases in four apparel categories: jeans, dresses, activewear and bras. About 18% of millennials are heavy purchasers of jeans, compared to 10% of Gen Xers and almost 8% of baby boomers. Millennial women are 1.4 times more likely to be heavy dress buyers than Gen Xers and 2.4 times more likely than boomers. When it comes to activewear, 20% of millennials are heavy purchasers, as opposed to 18% of Gen Xers and 11% of boomers. Millennial women make up 26% of heavy bra purchasers, compared to 23% of Gen Xers and 18% of boomers.

Those stats don’t tell the whole story though, according to the study. Instead, attributes like life stage (single or married, with or without children), lifestyle (active or more sedentary) and fashion attitude (fashion forward or traditional) are important when determining who will be a heavy purchaser of a particular apparel category.

For instance, parents are more likely to be heavy purchasers of comfortable clothing like jeans and activewear. Among millennials, 19% of parents buy jeans and 20% buy activewear. When it comes to dresses, those figures drop to 9%. For millennials with no children, however, dresses are much more popular, with 24% counted as heavy purchasers. Perhaps unsurprisingly, shoppers who have or want an active lifestyle were more likely to purchase activewear than couch potatoes. And fashionistas are heavy purchasers in all four categories, according to the study.

“Age is only one piece of the puzzle,” says Hana Ben-Shabat, a partner at A.T. Kearney and co-author of the study. “By targeting millennials as a cohort, retailers are missing the real drivers of purchasing. It’s important to target each segment and adjust your value proposition accordingly.”

The “Age Isn’t Everything” study is based on survey responses from 2,355 men and women in the United States who provided information on purchasing for jeans, activewear, dresses and bras. Heavy purchasers were defined as those who purchased three or more items in the same category in the past six months. The full report is available here.