Approximately 2.1 million people in the United States have been diagnosed with type 1 diabetes, according to the CDC’s National Diabetes Statistics Report. That total includes about 1.8 million adults aged 20 and older and 314,000 children and adolescents under 20.
How Type 1 Compares to Type 2
Type 1 diabetes accounts for roughly 5% to 10% of all diabetes cases in the U.S. The remaining 90% to 95% are type 2 diabetes, which develops when the body gradually loses its ability to use insulin effectively. Type 1 is fundamentally different: the immune system attacks the cells in the pancreas that produce insulin, leaving the body unable to make it at all. People with type 1 need insulin from the day of diagnosis for the rest of their lives.
Because type 2 dominates the overall numbers, most national diabetes statistics don’t distinguish between the two types. That can make type 1 seem rarer than it is. At 2.1 million people, the type 1 population is roughly the size of the entire city of Houston.
Adults Get It Too
Type 1 diabetes is sometimes called “juvenile diabetes,” but the name is misleading. Adults make up the clear majority of people living with the condition, with 1.8 million of the 2.1 million total being 20 or older. Many of these adults were diagnosed as children and have managed the disease for decades, but a significant number develop type 1 well into adulthood.
Adult-onset type 1 diabetes creates a real diagnostic problem. Research published in The American Journal of Managed Care found that one-third of people who develop type 1 after age 30 are initially misdiagnosed with type 2 and treated without insulin. That delay matters because without insulin, someone with type 1 can become dangerously ill. If you’re diagnosed with type 2 but aren’t responding well to standard treatments, antibody testing can determine whether type 1 is actually the cause.
Where Type 1 Is Most Common
Rates of type 1 diabetes vary dramatically across the country. A CDC study of people aged 19 and younger found a nearly 15-fold difference in prevalence between states. Vermont had the highest rate at about 80 per 10,000 young people, followed by Hawaii, Maine, Alaska, Montana, South Dakota, Wyoming, and New Hampshire. The lowest rates were in California, the District of Columbia, Maryland, Texas, and Louisiana.
The reasons behind this geographic variation aren’t fully settled, but researchers have pointed to differences in genetic background across populations, environmental triggers, and possibly variations in how consistently cases are captured in insurance data. Northern states with predominantly white populations tend to report higher rates, which aligns with the broader pattern that type 1 has historically been more common among people of European descent.
The Financial Reality
Managing type 1 diabetes is expensive even with insurance. A study led by the University of Michigan, based on national data from more than 65,000 patients with private employer-sponsored coverage, found that adults and children with type 1 spend an average of $2,500 per year out of pocket on healthcare. That figure covers insulin, continuous glucose monitors, pump supplies, test strips, and medical visits.
For some, costs run much higher. About 8% of patients in the study spent more than $5,000 out of pocket annually. Families with children who have type 1 faced especially steep supply costs, averaging $823 per year on diabetes-related supplies compared to $445 for adults. These figures only capture people with private insurance, so they don’t reflect the experience of uninsured individuals, who can face insulin costs of several hundred dollars per month on their own.
Life Expectancy Has Improved Significantly
A type 1 diagnosis once meant a dramatically shortened life, but outcomes have improved enormously over the past several decades. A U.S. cohort study found that life expectancy improved by 15.4 years between people diagnosed in the 1950s and early 1960s compared to those diagnosed in the late 1960s through 1980. That improvement has continued with the introduction of better insulin formulations, continuous glucose monitors, and insulin pumps that help people keep blood sugar in a tighter range.
The gap between type 1 life expectancy and the general population hasn’t fully closed, though. Long-term complications affecting the heart, kidneys, eyes, and nerves remain the primary drivers of reduced life expectancy, and they’re closely tied to how well blood sugar is controlled over years and decades. Modern technology has made that control far more achievable than it was even 10 or 15 years ago.