Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.
CCP 998 is not something that applies to workers' compensation. It has to do with offers being made to settle. If tthe defendant makes a 998 offer and you refuse it and then the case goes to trial and you get less than the offer, you have to pay the other side's costs. Again, this does not apply to workers' compensation.