Alberta NDP Leader Rachel Notley is promising to cover the full cost of prescription medications for lower-income seniors if she is re-elected on April 16.

The plan would cost the government $110 million a year.

Alberta seniors get drug costs covered under Blue Cross but they still have to pay 30 per cent of the cost, to a maximum of $25 per prescription.

The NDP's plan would eliminate those co-payments for seniors with annual incomes under $75,000. Notley said four out of five Alberta seniors would benefit from the plan.

Notley said the government looked at covering the full cost of seniors' medications but decided to propose this change instead.

"It would be obviously preferable to make it universal," she said. "But in a case like this we also have to balance the costs, and so we are hopeful that we've struck the right balance here."

Seniors who qualify would save an average of $200 each year.

The NDP said about 10 per cent of seniors with multiple prescriptions spend as much as $500 a year on co-payments.

Notley said the cost prevents some seniors from getting the medications they need.

Existing rules would continue to apply for seniors with annual incomes of more than $75,000.