How to appeal a medical bill

Please do not resubmit bills as this can delay the review process. Instead, use our online appeal
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Please do not resubmit a duplicate bill as this can delay the review process. Instead, use our online appeal function for quick and easy bill appeal.

Per Rule 16 of the Colorado Division of Workers’ Compensation (DOWC), the billing provider has 60 days to respond to the payer’s written notice to contest. If a response is not received in this time, the bill will not be considered for appeal.

Appeal Online

To appeal online, click the Sign in option in the top right corner of Then select Medical Provider.

  • Login with your email and password
  • Click the Bill Search tab and select the clinic Tax ID
  • Enter the claim number, bill number, date range or EFT/check number
  • Click the Search button
  • Select the bill you want to appeal
  • Click the Bill Detail tab
  • Click on Appeal
  • Provide the reason for the appeal and any additional comments in the text box
  • Upload optional supporting documentation as an attachment or by dragging and dropping
  • Click DONE to close the window
  • After uploading, select the appropriate file type based on the definitions below:
  • ~ Medical Record – documentation signed by a medical provider of services rendered or medical necessity. Documentation does not include any dollar figures.
  • ~ Bill – non-medical record that attaches to a bill to help process charges. May include dollar figures.
  • ~ Attachment – supporting documentation to the bill but is not a medical record.
  • Click Submit Request
  • A pop-up indicates the appeal was submitted and the bill detail will indicate the bill is in appeal
  • The user will receive an email indicating the bill appeal was received

Start your appeal

Appeal by Paper

If you wish to submit a paper appeal by mail:

Pinnacol Assurance
P.O. Box 469013
Denver, CO 80246

You may also fax an appeal to 303.361.5820 or email an appeal to

All appeals must include the following information:

  • A copy of the original or corrected bill
  • A copy of the written notice or EOB received
  • A statement of the specific item(s) contested
  • Clear and persuasive supporting documentation or clear and persuasive reasons for the appeal
  • Any available additional information requested in our written notice


If you have any questions or need additional information, please contact Pinnacol’s provider medical billing auditors at 303.361.4940 or

COVID-19 policy update