Billing manual for healthcare agency

I’m new start up and I’m trying to setup policies and procedures, the operational policies I purchased a manual and tweaked it based on regulations but the Billing how to manuals are not easily found. I have zero experience healthcare agency billing.

The external how to is on the web but its the internal how to is what I need help finding a manual.

Any suggestion

Billing rates and codes vary by state. Check your state’s Medicaid rate sheets and provider manuals for specific reimbursement details, and refer to CMS guides for federal billing standards.