Pre-condition, forced to change insurance plan

Hi, as my previous insurance company was not able to provide service this July (due to the cancellation of their business license), I was forced to change to another insurance company. There is no gap days between.
I had some medical treatment when I was under the previous insurance coverage, but the disease happened again to me after I changed to the new provider.
The new provider denied all my claim due to the pre-condition. Is there any way to dispute with them?
Many many thanks!!!!

[Amir Mostafaie]

Dear leelleel,

Assuming that you have an employer sponsored pan, it is unusual for a new carrier to impose a pre-existing exclusion on existing employee/members as long as you have has continuous coverage for 12 months prior to the new plan.

Your previous carrier should have sent you a certificate of credible coverage which is basically a letter that spells out how long and what type of coverage you had before.
Sometimes the new carrier may ask to see that letter to give you credit towards your past coverage and waive any waiting period or exclusions.

I recommend you reach out to the new carrier and ask them what they need from you in order to eliminate the waiting period.

Sincerely,

Amir Mostafaie