Want to make a switch in your Tricare health plan? You’ll have to do it by phone or by mail, because a glitch has shut down your online option — likely for the rest of open enrollment season.

And if you thought you’ve made a switch during this open enrollment season that began Nov. 11, you’d better call your Tricare regional contractor to make sure your new plan start date is Jan. 1, 2020, according to Tricare officials — so you don’t have a gap in coverage.

“We are not certain how many individuals were able to complete actions to change plans when they went online,” Tricare officials said in a response to questions.

There is no telling right now how many beneficiaries may be affected by this glitch.

Open enrollment ends on Dec. 9. It’s the annual period when beneficiaries can change between their Tricare Prime Option or Tricare Select health plan. This is the only time of the year that beneficiaries can change plans, other than because of a qualifying life event, such as marriage, retirement from active duty, or birth.

Those who want to stay in their current Tricare health care plan don’t have to take any action.

The web enrollment will likely remain unavailable throughout the open season for beneficiaries who want to change plans, according to Tricare officials. However, it will be available for new enrollments, such as those retiring from active duty, and those who have a qualifying life event.

Officials learned about the problem as a result of comments on their social media channels; they are investigating the causes.

In the absence of the online option, here’s how you can make changes in the enrollment::

By phone

Call your regional contractor:

*Health Net Federal Services (Tricare West): 1-844-866-9378

*Humana Military (Tricare East): 1-800-444-5445

*Visit a Tricare Service Center or contact International SOS (Overseas only)

By Mail

Mail an enrollment form. Download that form at https://www.tricare.mil/forms

Each Tricare plan has its own features and cost structure.

Tricare Prime has no out-of-pocket costs for active duty families, unless they see a doctor outside their Prime network without a referral, or fill prescriptions at a retail pharmacy or through mail order. For retirees, Tricare Prime requires an annual enrollment fee as well as co-payments for appointments and procedures other than those at a military treatment facility.

Tricare Select for most beneficiaries requires no enrollment fee but has a higher fee structure. It allows beneficiaries to select their own physicians and see specialists largely without a referral.

Beneficiaries can compare options on the Tricare website. (It’s the enrollment function of the site that’s not currently working.)

Military Times Health Care Reporter Patricia Kime contributed to this report.