SACRAMENTO, Calif. — California is harming medical care for more than 13 million lower-income residents, more than half of them Latinos, by failing to pay doctors enough to provide proper care, according to a lawsuit filed Wednesday.

The lawsuit alleges the state violates Latinos' civil rights because poorly paid health care providers balk at providing treatment.

It alleges the low reimbursements often mean that those who rely on Medi-Cal, the state's health care program for the poor, are denied timely and quality medical care. The lawsuit was filed in Alameda County Superior Court by plaintiffs including the state's largest labor union representing health care workers.

"In effect, California has created a separate and unequal system of health care, one for the insurance program with the largest proportion of Latinos (Medi-Cal), and one for the other principal insurance plans, whose recipients are disproportionately white," the suit says.

The suit was filed by five Latino residents who depend on Medi-Cal. They were joined by the community division of the Service Employees International Union-United Healthcare Workers West. The Oakland-based union includes 93,000 caregivers, while the community division has 6,000 union supporters including Medi-Cal patients.

About 7.2 million Latinos are on Medi-Cal, a program that covers low-income families, some elderly patients, those with disabilities, foster children and pregnant women.

The California Department of Health Care Services "has not identified any systemic problems with patient access to services in the Medi-Cal program," nor have federal officials, department spokeswoman Carol Sloan said in an emailed statement.

She declined further comment, but provided a letter state officials sent to the plaintiffs' lawyers last year saying there is no evidence of discrimination against Latinos. That letter was written after some of the same Medi-Cal recipients filed a similar civil rights complaint against the state with the U.S. Department of Health and Human Services in 2015.

One of those suing is 33-year-old Saul Jimenez Perea of Clearlake, who has cerebral palsy and suffers severe seizures that require frequent hospitalizations. It took months for Perea to see several specialists since he is covered by Medi-Cal, according to the lawsuit.

"People who are going through the medical system, they're not being treated fairly, particularly if they have a certain type of insurance," he said in a telephone interview.

"It broke my heart, seeing these people getting worse, like my son, or some actually died," added Analilia Jimenez Perea, 56.

The state budget includes $107 billion in state and federal funding for Medi-Cal this year, but the spending is not enough to restore reimbursement cuts made during the Great Recession. A proposal in the U.S. Senate to repeal former President Barack Obama's health care overhaul law could drastically reduce money for Medi-Cal and the number of Californians who can access it.

Thomas Saenz, an attorney with the Mexican American Legal Defense and Educational Fund who helped file the lawsuit, said he believes it is the first time the civil rights approach has been tried in California. The legal approach is possible, he said, because California is one of the few states to specifically prohibit discriminatory effects in state programs.

Those receiving care through Medi-Cal have substantially worse access to health care than those who are covered by Medicare, which provides care for the elderly, or employee-sponsored insurance, according the lawsuit. That's because there are a relatively low number of Medi-Cal providers, partly because they are underpaid, the lawsuit says.

The lawsuit claims that those on Medi-Cal suffer more illness and more undiagnosed and untreated serious medical conditions than do other Californians with different insurance.

It blames Medi-Cal reimbursements that it says are among the lowest in the nation and a fraction of what other insurance plans pay providers. California ranks 48th or 49th out of 50 programs, it says, depending on the payment method.

Those payments have steadily dwindled since 2000, the suit says, even as the number of Latinos in the program has tripled.