CO Rev. Stat §10-16-106.5(5)(a)

(b) A carrier that fails to pay, deny, or settle a claim in accordance with subsection (4) of this section within ninety days after receiving the claim shall pay to the insured or health care provider, with proper assignment, a penalty in an amount equal to twenty percent of the total amount ultimately allowed on the claim.  Such penalty shall be imposed on the ninety-first day after receipt of the claim by the carrier.