An estimated 9.5 million people worldwide are living with type 1 diabetes. That number has grown steadily over the past two decades, and modeling published in The Lancet Diabetes & Endocrinology projects it will reach 13.5 to 17.4 million by 2040, a 60 to 107 percent increase from 2021 levels.
Type 1 Diabetes in the United States
Type 1 diabetes accounts for roughly 5 to 10 percent of all diagnosed diabetes cases among U.S. adults. With about 38 million Americans living with diabetes overall, that puts the estimated adult type 1 population somewhere between 1.9 and 3.8 million. Among young people, the CDC reported just over 21,700 new youth diagnoses in 2022 alone.
Those numbers may actually undercount the true population. Research in Diabetes Research and Clinical Practice found that at least 10 percent of adults with type 1 diabetes are initially misdiagnosed with type 2, and other studies show that 4 to 14 percent of people classified as having type 2 diabetes test positive for the autoimmune markers that define type 1. Many of these individuals spend years on the wrong treatment plan before receiving a correct diagnosis.
It’s Not Just a Childhood Disease
Type 1 diabetes has long been called “juvenile diabetes,” but that label is misleading. According to the International Diabetes Federation, 62 percent of all new type 1 diagnoses in 2022 occurred in people aged 20 or older. Adults who develop it later in life are the ones most likely to be misdiagnosed, partly because doctors expect type 1 to appear in childhood and may default to a type 2 diagnosis in an older patient.
Who Is Most Affected
Type 1 diabetes occurs across all racial and ethnic groups, though overall diabetes rates vary significantly by population. CDC data for 2021 to 2023 show that 12.2 percent of non-Hispanic Black adults and 11.8 percent of Hispanic adults have diagnosed diabetes, compared to 7.1 percent of non-Hispanic white adults. New diagnosis rates follow a similar pattern: 9.1 per 1,000 for Black adults and 9.0 per 1,000 for Hispanic adults, versus 5.1 per 1,000 for white adults. These figures cover all types of diabetes combined, but they reflect broader disparities in access, diagnosis timing, and health outcomes that also shape the type 1 experience.
How Type 1 Affects Life Expectancy
A 2025 meta-analysis in Frontiers in Endocrinology compared life expectancy across large populations. Men with type 1 diabetes lived an average of 65 years, and women lived about 68 years. That translates to roughly 11 fewer years of life for men and nearly 11 fewer for women compared to people without diabetes, who averaged about 80 and 84 years respectively.
Those gaps are narrowing as insulin delivery and blood sugar monitoring technology improve, but they remain significant. By comparison, type 2 diabetes shortened life expectancy by about 5 to 7 years in the same analysis, reflecting the more intensive daily management burden that type 1 requires.
The Cost of Daily Management
Living with type 1 diabetes means paying for insulin, glucose monitors, pump supplies, test strips, and regular medical visits, every year, for life. Research from Michigan Medicine found that adults and children with type 1 spend an average of $2,500 a year in out-of-pocket health care costs. Insulin itself accounted for only about 18 percent of that total. Diabetes-related supplies like insulin pumps, syringes, and continuous glucose monitors actually cost more than the insulin they help deliver.
Families with children who have type 1 face especially high supply costs, averaging $823 per year on devices and supplies alone compared to $445 for adult patients. And 8 percent of all patients in the study spent more than $5,000 out of pocket annually, more than double the average.
A Growing Global Problem
The projected rise to as many as 17.4 million cases by 2040 will hit lower-income countries hardest. The Lancet modeling predicts the largest relative increases in low-income and lower-middle-income nations, where access to insulin, refrigeration, and monitoring technology is already limited. In some of these countries, a type 1 diagnosis still carries a dramatically shorter life expectancy simply because consistent insulin supply cannot be guaranteed.
The reasons behind the global rise remain partly unclear. Type 1 diabetes is an autoimmune condition in which the body’s immune system destroys the cells in the pancreas that produce insulin. Genetics play a role, but environmental triggers are likely contributing to the increase, since genetic changes alone cannot explain growth rates this rapid across just a few decades.