Gov. Jan Brewer signed into law Friday a measure allowing some religious employers to opt out of covering prescription contraceptives as part of their health-care plans.

House Bill 2625 applies only to "religiously affiliated" employers, which are defined as non-profit groups that primarily employ and serve individuals of the same religion or religiously motivated organizations with articles of incorporation clearly stating that religious beliefs are central to the organization's operating principles.

The original version of the bill would have allowed any employer to opt out, but it was narrowed to get enough legislative support.

Opponents said the law attacks a woman's right to make her own health-care choices. Brewer said the law is about religious freedom.

"Mandating that a religious institution provide a service in direct contradiction with its faith would represent an obvious encroachment upon the First Amendment," she said in a news release.