WASHINGTON (NewsNation) — Biden administration officials are trying to encourage as many U.S. military veterans as possible to submit a claim to receive PACT Act retroactive benefits by Wednesday.

Hundreds of thousands of veterans have received additional benefits in the past year after President Joe Biden signed legislation expanding coverage for conditions connected to burn pits that were used to destroy trash and potentially toxic materials. 

While there’s no deadline to submit a PACT Act claim or “intent to file” to receive benefits, there is a deadline of Aug. 9 to qualify for retroactive benefits backdated to Aug. 10, 2022, according to the U.S. Department of Veterans Affairs.

Under the law, certain cancers and ailments are presumed to be connected to the burn pits that were used to dispose of trash and potentially toxic materials. For veterans who served during the Vietnam War, hypertension and other conditions were added to the list of problems presumed to be caused by exposure to Agent Orange, which was used by the military to clear vegetation.

The VA called the legislation one of the largest health care and benefit expansions in VA history.

About 111,000 veterans who are believed to have toxic exposure have enrolled in VA health care since the law was enacted. In addition, more than 4.1 million veterans have completed toxic screenings, which are questionnaires to analyze their potential exposure and determine whether additional tests are required.

Implementing the legislation has proved challenging for the VA despite hiring new staff to accommodate a historic influx of claims. The backlog is about 266,000, meaning waits of at least four months for claims to be processed, and the list is expected to grow to 450,000 in October and 730,000 in April.

Since the act was signed into law, the VA asserts it has distributed more than $1.4 billion in related benefits.

According to administration statistics, the VA has received nearly 786,000 disability claims under the PACT Act, processed almost 435,000 and approved more than 348,000.

Gulf War veteran Tim Hauser joined the movement calling for change after experiencing firsthand the struggle to receive benefits related to health issues from being exposed to toxic burn pits. He said being able to receive benefits has impacted many veterans.

“The veterans that are actually taking advantage of this bill, it’s changing their life so much,” Hauser said. “They don’t have to worry about do I pay for my medications today or do I pay for rent. They’re going to be able to pay both now.”

Biden will mark the law’s anniversary at a Veterans Affairs hospital in Salt Lake City on Thursday.

Veterans only need to file an “intent to file” application Wednesday. They’ll then have a full year to complete the necessary paperwork to receive benefits.

This also covers benefits for veterans family and spouses.

For additional details about filing for PACT Act benefits, go to VA.gov/PACT. If calling is more convenient, call the VA benefits hotline at 1-800-827-1000.

The Associated Press contributed to this report.