The rule approved Tuesday by the Office of Administrative Law allows Jones to require insurers to spend 80 percent of premiums collected from individual policyholders on medical care, instead of 70 percent.
Insurers can use the money not spent for medical care for administrative costs or profits.
The change reflects new rules under federal health reform, which went into effect this year but is being threatened by opponents in Congress. Opponents at the federal level, chiefly freshmen Republican congressmen, say they will kill funding for enforcement.
Jones requested the regulation as his first act when he took office this year.