The Department of Health and Welfare is reporting some “concerning” numbers: Idaho has the highest percentage of immunization exemptions for kindergartners.

According to 2014-15 Centers for Disease Control data, 6.5 percent of kindergartners were exempted from at least one immunization. That’s up from a 6.4 percent rate in 2013-14, when Idaho’s exemption rate was second-highest in the nation, trailing only Oregon.

Parents can seek an exemption on philosophical, religious or medical grounds. The vast majority of exemptions are based on philosophical grounds.

An exemption does not necessarily mean a child does not have an immunization. Sometimes, parents fill out a form simply because their child is behind on immunizations, and they want to register their child for school. Parents can claim a waiver by filling out a two-page form available on the Health and Welfare website.

“Having a high percentage of students who are not fully protected from preventable diseases is concerning, especially for other children who cannot receive vaccine protection because of medical conditions,” Dr. Christine Hahn, the state’s public health medical director, said on a Health and Welfare blog post. “Many parents sign an exemption for convenience; it may be the path of least resistance when registering a child for school who is behind on their vaccine schedule. However, that path can lead to serious illness to their children or classmates. We believe Idaho can do better.”

The kindergarten immunization rate for most recommended vaccines is nearly 90 percent. For the two-shot chicken pox immunization — the vaccine with the highest exemption rate — 88.1 percent of kindergartners were current on their shots.

More reading: More from Melissa Davlin of “Idaho Reports,” who first wrote about the new immunization numbers on her blog Thursday.