AUGUSTA (AP) — Nearly 20,000 Maine customers of health insurer Aetna are getting premium rebates because a provision in the Affordable Care Act limits what insurance companies can spend on administrative costs.

The rebates for 2013 service, totaling more than $1.8 million, will be issued by Aug. 1.

The Portland Press Herald (http://bit.ly/1xaHxyA ) reported that most will be in the form of temporary premium reductions although some customers might receive checks. The average payment will be $149 for thousands of the insurer’s Maine customers with employer-based plans.

The rebates are the result of the “medical loss ratio” rule that caps administrative spending. The law is meant to protect consumers by ensuring that extra profits made by insurance companies would be rebated to customers and not used for executive bonuses or other administrative costs.