Rotech Healthcare, Inc., of Orlando, a large provider of respiratory therapy and HME products, last week reported that it had identified an error in its billing system that resulted in overpayment of Medicare claims. The overpayments totaled about $2.2 million each fiscal year for 2009, 2010 and 2011.

“The company has voluntarily issued refunds related to the aforementioned overpayment,’’ Rotech said in a press release outlining its first quarter 2012 financial results.

The company also posted higher than normal rates of contractual revenue and bad debt adjustments totaling $9.6 million. That was caused by delays in obtaining necessary billing paperwork while implementing a new electronic order intake system late last year, the company reported.

Rotech also reported a reduction in nebulizer reimbursement of $4.1 million for the first quarter of 2012 compared to the same period last year.

The company did report a 5 percent increase of revenue-generating patients using oxygen and CPAP in the first quarter of this year compared to the same period a year ago.