Minnesota's hospitals reported Thursday that they covered $509 ­million in uncompensated medical care in 2011, an increase of 2.6 percent from a year earlier.

The Minnesota Hospital Association's report, which details the benefit the state's 144 health care organizations say they bring to the community, indicated that hospitals continue to cover "a substantial and growing proportion" of medical services without getting paid.

Bad debt from patients who are uninsured or don't pay their share of the bills increased 4.4 percent, to $281 million at the state's hospitals and clinics. Charity care, which includes free or discounted medical treatment to those who can't afford to pay, was up less than 1 percent from a year earlier, at $227.7 million.

The association said it also is seeing a growing gap in reimbursement from state and federal governments for care provided to seniors and low-income patients ­covered by public health plans. The gap from underfunded care for patients receiving Medicare and Medicaid grew by 26 percent during the year.

The report comes as the industry group lobbies the state Legislature to support key elements of the Affordable Care Act, including expanding Medicaid to include more Minnesotans and a state-run insurance exchange that will make it easier for individuals and small businesses to buy affordable insurance.

"As nonprofits, hospitals and health systems provide access to care to patients — regardless of their ability to pay — 24 hours a day, seven days a week," Lawrence Massa, CEO of the Minnesota Hospital Association, said in a statement.

The state Department of Health, which uses the same data, reported a lower figure of $308 million earlier this week for uncompensated care. The state's number doesn't include gaps in Medicare or information from clinics, nursing homes and other businesses aside from the hospital.

As part of the new health care law, hospitals are required to more clearly report ­charitable activities and other community benefits to the IRS to justify their tax-exempt ­status.

Minnesota hospitals put the total value of community contributions at $3.6 billion in 2011, an increase of 7 percent. The figure includes education and workforce development, as well as services such as health screenings and stop-smoking efforts, in addition to uncompensated care.