Montana, Idaho, Oregon, Louisiana and Oklahoma have the highest percentage of military veterans who don’t have health insurance, with Montana’s rate of 17.3% the highest, a new report says. 

The lowest percentage of the uninsured non-elderly veterans live in Massachusetts (4.3% state rate), Hawaii, Vermont,  North Dakota and Connecticut.

All told 1.3 million veterans — 10.5% — and 940,000 family member don’t have insurance, according to the report from the Urban Institute and Robert Wood Johnson Foundation. (Download PDF).  That compares to about 18% for all U.S. residents.  Younger, single, less-educated veterans with fewer ties to the workplace tend to be more likely to not have insurance.

The report is based on 2010 data.

The federal Affordable Care Act could help increase coverage, the report suggests. “We estimate that nearly half of uninsured veterans would qualify for expanded Medicaid  coverage. Another 40 percent of uninsured veterans  could potentially qualify for subsidized coverage through  health insurance exchanges if they do not have access to affordable employer coverage.” The U.S. Supreme Court is expected to release its decision this week related to a key provision of the act.

Harvard’s Joan Shorenstein Center has a summary of the report’s findings.