WOONSOCKET, R.I. – CVS Corp. agreed Thursday to pay $1.1 million to settle claims it violated consumer protection laws in nearly 20 states, including Maine, by allegedly charging full price for partially filled prescriptions.

Attorneys general in 18 states and the District of Columbia claimed the Woonsocket-based pharmacy chain improperly accepted full payment for prescriptions that could be filled only partially due to insufficient stock.

If the consumers did not return to pick up the remainder of the prescription, CVS kept the excess payment, the attorneys general alleged.

“CVS cannot shortchange customers – a legal standard that this settlement enforces. Accepting payments in full while filling prescriptions only in part is unethical and illegal,” said Connecticut Attorney General Richard Blumenthal. “As big as it is, CVS must realize that completely filling prescriptions is no small matter.”

CVS spokesman Todd Andrews said the claims stem from before 1998, and since then, the company has changed its procedures. He said accepting payments for so-called “partial-fills” was an industrywide practice at the time.

“Any isolated instances of incorrect billing for partially filed prescriptions were inadvertent,” Andrews said.

The pharmacy chain did not admit any wrongdoing as part of the settlement but agreed to pay $700,000 to the states and the District of Columbia plus an additional $400,000 in lieu of repayments to affected consumers, which were judged too difficult to calculate.

The states must use their portion of the $400,000 to benefit low-income, disabled or elderly people who take prescription medications.

The settlement also requires CVS to develop and implement policies that prevent improper billing.

Andrews said the company believes its current practices are in full compliance with state and federal regulations.

The states involved in the settlement are Alabama, Connecticut, Delaware, Georgia, Illinois, Kentucky, Maine, Maryland, Massachusetts, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Vermont and West Virginia.