If your client changes insurance companies do not delete the old insurance company from the client's record. Instead, you want to add the additional insurance company by going to the client's Edit info page and clicking on the Billing and Insurance tab.
By clicking the +Insurance info link in the Insurance section of the page, you will be able to add the new primary insurance and set the old insurance to Other. This way, you will still be able to add, edit, and delete insurance payments that have appointments associated with the old insurance.
For the new Insurance Type set it to Primary if it is the client's new primary insurance. If you are adding a secondary insurance, you can set the insurance type to Secondary.
Note: Make sure that the old insurance plan type is switched to Other.
After you click Save, you'll be all set to start billing the new insurance while still keeping their old insurance on file. Now you'll have the option to apply an insurance payment to this client's account from any of the insurance companies you have on record.