There is not a universal practice. Predominantly just excel, a lot of emails, conference calls and meetings. Different institutions have distinct personalities

There is not a universal practice. Predominantly just excel, a lot of emails, conference calls and meetings. Different institutions have distinct personalities and that reflects in how things are done between them. Some people still have actual mainframes involved. When it comes to large parties, multi-practice groups, health systems, etc, an overall fee schedule or charge master for an existing institution is typically not renegotitated line by line every year but as incremental changes from the previous. Many/most of the parties involved have been working together for decades, some even longer. Many plans administered by familiar names like Anthem are actually funded and controlled by the large employers the plan services. In those cases the employer plays a role in defining what will and will not be covered and what will be paid and the insurer is a middleman (acting as a third party administrator).