Fifty-five hospitals in 21 states have agreed to pay $34 million to the U.S. government to settle allegations that they used more expensive inpatient procedures rather than outpatient spinal surgeries to get bigger payments from Medicare.

The Justice Department announced the settlement Tuesday over kyphoplasty procedures used to treat usually caused by osteoporosis.

The procedure can be performed on an outpatient basis. But the Justice Department says the hospitals performed the surgeries inpatient to increase Medicare billings.

A similar settlement was reached last year, when 14 hospitals agreed to pay a settlement of more than $12 million.