Lawmakers are demanding answers from Veterans Affairs officials after a new investigation found more than $53 million in emergency room costs for veterans improperly rejected by department officials.

In a letter to VA Secretary Robert Wilkie this week, the bipartisan group of 35 House and Senate members asks for an explanation for how more than 17,000 veterans were left with unpaid, unjustified medical bills and what plans the federal bureaucracy has to correct the mistakes.

“Facing a medical emergency can be stressful for any patient," the letter stated. "However, the financial toll on veterans when VA erroneously denies or rejects payment can also be devastating. Hospitals may send veterans’ emergency care bills to collection. Non-payment can bankrupt and destroy veterans’ credit histories.”

At issue is a report from the VA Inspector General released earlier this month which found $716 million in improperly processed payments in cases involving veterans who sought medical care outside the department’s health system during the spring and summer of 2017.

Not all of the mistakes lead to denied payments, but investigators estimated about 7 percent of the total resulted in veterans receiving bills that should have been covered under existing VA rules.

Investigators found cases of claims being incorrectly rejected because paperwork was filed too late, because of errors in outside-care eligibility, and because processors missed clinical records ordering the outside care. They also found lax oversight within VA, with numerous cases of supervisors not reviewing decisions for quality or accuracy checks.

“It is critical that VHA staff process claims for non-VA emergency care in an accurate and timely fashion,” the report stated. “Inappropriately denied or rejected non-VA emergency care claims present a risk of substantial, undue financial burden on veterans.”

Complicating the problem was mistakes in VA’s process of notifying veterans about their rejected medical payment claims, which lead to thousands of veterans missing out on a chance to appeal the decisions.

VA officials in response to the report said they have already put numerous fixes in place to deal with the problems from two years ago and should implement the rest of the Inspector General’s recommendations later this year.

They also promised to review patient cases as far back as April 2016 to ensure that veterans improperly denied medical coverage are helped. Letters informing those veterans of possible avenues of appeal or redress will be sent out in coming months.

Lawmakers in their letter say they want more details of that promise, to ensure similar mistakes aren’t made in the future.

They also asked department officials to report “whether VA is appropriately resourced — in terms of staffing and technology — to implement requirements associated with emergency care claims adjudication.”

Inspector General officials said if proper fixes aren’t fully implemented, the unexpected costs to veterans seeking outside care could grow to more than $500 million over the next five years.