The Veterans Administration operates the country’s largest health-care system, with more than 1,400 hospitals employing nearly 15,000 doctors. That expansive system does not, however, cover everyone: One in 10 veterans currently lack health insurance, according to a new Urban Institute study.

Uninsured veterans are more likely to be unemployed or have a lower-income job. (George Frey/GETTY IMAGES)

The Veterans Health Administration does provide coverage for most veterans, although not all: Eligibility is determined in part by factors including income, injuries sustained in combat and length of service.

The eligibility requirements leave 1.3 million veterans without health care benefits, alongside 0.9 million members of their families.

Uninsured veterans tend to be younger than those with coverage and also less likely to have sustained an injury in combat. Uninsured veterans also tend to have higher rates of unemployment and lower levels of income and are less likely to be married — all of which lower the odds of receiving private coverage.

“Their lower likelihood of being full-time workers and being married likely contribute to their lack of coverage, as these attributes are characterized by lower access to employer-sponsored health insurance,” write Jennifer Haley and Genevieve Kenney.

The expansion of coverage under the Affordable Care Act could lower the uninsured rate among veterans — not by targeting them specifically, but by expanding health insurance to lower-income populations. Nearly half the uninsured veterans would become eligible for Medicaid, which will expand to cover all those with incomes under 133 percent of the Federal Poverty Line. Others will qualify for subsidies to purchase private insurance coverage on the individual market.