50 Ill. Adm. Code 2908.10
Applicability
Section 2908.10 Applicability
Every employer and insurer, or the employer's or insurer's
payer or payer's agent, and every third party administrator must accept
electronic claims for payment of medical services as provided by Section 8.2a
of the Act. Every health care provider or facility rendering treatment
pursuant to the Act must submit medical bills for payment on standardized forms
either electronically or on paper as provided by Section 8.2a of the Act.