Each payer or insurance has its own payer ID number to accept electronic claims. It serves as the electronic address, so the clearinghouse knows which payer/insurance company should receive the claim.
Some national payers, such as Aetna (60054), Cigna (62308), and United Healthcare (87726) have universal payer IDs that can be used across all clearinghouses. Other payers can have different payer ids based on the clearinghouse.
Payer IDs that start with PRNT or GPRNT are claims that will be submitted to the payer on paper. Others with a numeric payer id, are submitted electronically. There is a $0.78/per claim charge for claims submitted on paper. There is no additional charge for claims submitted electronically.
Here is the link to TriZetto's payer listing that you will be using through DrChrono:
You can toggle between professional and institutional claims by clicking "Switch to Institutional Payer List" on the top left of the screen.