Walgreens has agreed to pay $300 million to settle U.S. prosecutors' allegations that it illegally filled millions of invalid prescriptions for opioids and other controlled substances, the U.S. Justice Department said Monday.

The money, plus 4% interest annually, will be paid out over six years under the terms of the agreement. Walgreens will also owe the U.S. an additional $50 million if the company is sold, merged, or transferred prior to fiscal year 2032, the Justice Department said.

Walgreens said in a filing with the U.S. Securities and Exchange Commission on Friday that the case was "the last anticipated major opioid regulatory matter" and that it had settled without admitting wrongdoing "to avoid the cost and uncertainty of continued litigation."

The government's January lawsuit alleged Walgreens ignored "red flags" that prescriptions were illegal and filled them anyway, violating the Controlled Substances Act. The government also alleged it violated the False Claims Act when it then sought reimbursement from federal health care programs, like Medicare, for the prescriptions.

Walgreens is among the drug manufacturers, distributors, pharmacy operators and others who have collectively in recent years agreed to pay about $50 billion to resolve lawsuits and investigations by states and local governments accusing them of helping fuel a deadly opioid addiction epidemic in the U.S.

Walgreens in 2022 agreed to pay up to $5.52 billion over 15 years to resolve thousands of lawsuits by state and local governments accusing the company of fueling the U.S. opioid epidemic.

The U.S. Centers for Disease Control and Prevention says nearly 727,000 opioid overdose deaths occurred from 1999 to 2022.