Requires that employers pay all workers' compensation claims for compensable injuries and not deny claims without reasonable cause or during a pending investigation. Creates a presumption of compensability for claims submitted by employees excluded from coverage under the Hawaii prepaid health care act. Requires that employers notify medical services providers of any billing disagreements and allows providers to charge an additional rate to employers for outstanding balances owed for undisputed charges. Establishes dispute resolution procedures for employers and providers who have a reasonable disagreement over charges. Requires employers to deny a treatment plan within 3 days of receipt of a treatment plan or the treatment plan is deemed accepted.