— North Carolina's largest insurer has decided to provide family health coverage to same-sex couples under the Affordable Care Act.

Blue Cross Blue Shield of North Carolina had previously canceled the family policies of some gay couples married in other states and told them to reapply for coverage as individuals.

Brad Wilson, Blue Cross president and chief executive, apologized for the cancellations, blaming the company's decision to delay upgrades to plans under the health law until 2015.

"One of these was to begin making family coverage available to same-sex married couples and domestic partners (same-sex or opposite-sex) in our ACA-approved plans," Wilson said in a statement. "We should have more thoughtfully considered this decision, with full appreciation of the impact it would have on same-sex married couples and domestic partners. We’re sorry we failed to do so."

Blue Cross has worked with state and federal regulators in recent weeks to update plans to allow the change in coverage.

Same-sex couples and anyone in a domestic partnership may, beginning Monday, purchase family coverage either directly from Blue Cross or on the HealthCare.gov exchange, the company said. Coverage would become effective March 1. Also, domestic partners and same-sex couples who enrolled separately on ACA plans also can convert them into family plans, retroactive to their original effective date.

Small businesses will have the option to offer coverage for same-sex couples and domestic partners, beginning with new and renewed plans effective April 1, the company said.

"We appreciate our customers’ willingness to bear with us as we work to make these changes quickly," Wilson said.