At least 3 more health insurers will be getting an early start on making dependent coverage continuation benefits available to graduating college students.

The carriers – Humana Inc., Louisville, Ky. (NYSE:HUM); Kaiser Permanente, Oakland, Calif.; WellPoint Inc., Indianapolis (NYSE: WLP) – have joined UnitedHealth Group Inc., Minnetonka, Minn., (NYSE: UNH) in announcing plans to let graduating seniors who now get coverage through their parents’ plans keep that coverage until they turn 26.

The young adult coverage continuation provision in the Patient Protection and Affordable Care Act is not set to take effect until Sept. 23.

U.S. Health and Human Services Secretary Kathleen Sebelius had asked carriers to address the coverage gap.

“Following our initial conversations and outreach to insurers, we are encouraged by the actions of WellPoint, United Healthcare and other companies to bridge the gap between now and the fall when the [PPACA] law becomes effective,” Sebelius says in a statement. “We are also working hard with other insurers on similar proposals and sent a letter today offering to work with each of them to expand this opportunity even further.”

UnitedHealth already has been letting holders of individual coverage keep adult children on their plans until the children are 26.

Starting June 1, WellPoint will offer the continuation option both to the children of group plan members and individual health policyholders.

Self-insured clients and members will have the option of not offering this extended coverage, WellPoint says.

Humana says its decision affects the adult children of members who are enrolled in the company’s fully insured group plans. Like UnitedHealth, Humana already lets adult children of individual policyholders stay on their parents’ or guardians’ coverage until age 26.

Humana is also encouraging large employers that self-fund their coverage with Humana to extend coverage to the adult children of employees who would otherwise lose coverage this year.

Pushing up the effective data of the coverage continuation provision will “enable young, overwhelmingly healthy people, who will not engender large health care costs, to stay in the insurance pool and retain important insurance coverage,” Sebelius has written in a letter to insurers. “Taking this step will also save money for your companies by avoiding the administrative costs of dis-enrolling and then re-enrolling young adults. Avoiding this gap would also eliminate an unnecessary inconvenience and disruption in health insurance coverage for both young adults and their parents.”