CO (Contractual Obligation) Denial Codes

CO adjustments mean the payer adjusted the claim based on your contract with them. The provider bears the financial responsibility — you cannot bill the patient for CO adjustments. CO is the most common Group Code in medical billing. These adjustments typically indicate billing errors that need correction and resubmission, fee schedule differences between billed and contracted rates, or coding issues.

Common scenarios: Billing errors that need correction and resubmission. Fee schedule differences between billed and contracted rates. Bundling adjustments where services are not paid separately. Timely filing limit exceeded.

Codes: 262 active Financial responsibility: Provider Patient billable: No
Disclaimer
This content is for informational purposes only. Always verify against your payer contracts and current coding guidelines.

All CO Denial Codes

Code Name Category Action
CO-1 Deductible Amount patient responsibility Review & Decide →
CO-2 Coinsurance Amount patient responsibility Review & Decide →
CO-3 Co-payment Amount patient responsibility Review & Decide →
CO-4 Procedure Code / Modifier Mismatch coding error Resubmit →
CO-5 Procedure Code Inconsistent with Place of Service coding error Verify & Resubmit →
CO-6 Procedure Inconsistent with Patient Age coding error Verify & Resubmit →
CO-7 Procedure Inconsistent with Patient Gender coding error Verify & Resubmit →
CO-8 Procedure Inconsistent with Provider Specialty coding error Verify & Resubmit →
CO-9 Diagnosis Inconsistent with Patient Age coding error Verify & Resubmit →
CO-10 Diagnosis Inconsistent with Patient Gender coding error Verify & Resubmit →
CO-11 Diagnosis Inconsistent with Procedure coding error Verify & Resubmit →
CO-12 Diagnosis Inconsistent with Provider Type coding error Verify & Resubmit →
CO-13 Date of Death Precedes Date of Service information missing Verify & Resubmit →
CO-14 Date of Birth Follows Date of Service information missing Verify & Resubmit →
CO-16 Missing Information or Billing Error information missing Verify & Resubmit →
CO-18 Exact Duplicate Claim or Service duplicate Verify & Resubmit →
CO-19 Workers' Compensation Claim coverage Verify & Resubmit →
CO-20 Liability Carrier Responsible coverage Verify & Resubmit →
CO-21 No-Fault Carrier Responsible coverage Verify & Resubmit →
CO-22 Care Covered by Another Payer (COB) coverage Verify & Resubmit →
CO-23 Impact of Prior Payer Adjudication other Review & Decide →
CO-24 Charges Covered Under Capitation or Managed Care fee schedule Review & Decide →
CO-26 Expenses Incurred Prior to Coverage coverage Verify & Resubmit →
CO-27 Expenses Incurred After Coverage Terminated coverage Verify & Resubmit →
CO-29 Timely Filing Limit Expired timely filing Appeal →
CO-31 Patient Not Identified as Insured information missing Verify & Resubmit →
CO-32 Patient Not Eligible as Dependent coverage Verify & Resubmit →
CO-33 Insured Has No Dependent Coverage coverage Verify & Resubmit →
CO-34 No Newborn Coverage coverage Verify & Resubmit →
CO-35 Lifetime Benefit Maximum Reached coverage Review & Decide →
CO-39 Services Denied at Pre-Certification authorization Appeal →
CO-40 Charges Not Qualifying as Emergent/Urgent Care coverage Appeal →
CO-44 Prompt-Pay Discount fee schedule Review & Decide →
CO-45 Charge Exceeds Fee Schedule / Maximum Allowable fee schedule Review & Decide →
CO-49 Routine/Preventive Exam Not Covered coverage Verify & Resubmit →
CO-50 Non-Covered Services / Medical Necessity Denial coverage Appeal →
CO-51 Pre-Existing Condition Exclusion coverage Appeal →
CO-54 Multiple Physicians/Assistants Not Covered coverage Review & Decide →
CO-55 Experimental / Investigational Procedure coverage Appeal →
CO-56 Procedure / Treatment Not Deemed Effective coverage Appeal →
CO-58 Invalid Place of Service / Treatment Setting Mismatch coding error Resubmit →
CO-59 Multiple / Concurrent Procedure Payment Reduction fee schedule Review & Decide →
CO-60 Outpatient Services Not Covered Near Inpatient Stay bundling Review & Decide →
CO-61 Second Surgical Opinion Not Obtained authorization Verify & Resubmit →
CO-66 Blood Deductible fee schedule Review & Decide →
CO-69 Day Outlier Amount fee schedule Review & Decide →
CO-70 Cost Outlier Adjustment fee schedule Review & Decide →
CO-74 Indirect Medical Education Adjustment fee schedule Review & Decide →
CO-75 Direct Medical Education Adjustment fee schedule Review & Decide →
CO-76 Disproportionate Share Adjustment fee schedule Review & Decide →
CO-78 Non-Covered Days / Room Charge Adjustment coverage Review & Decide →
CO-89 Professional Fees Removed from Charges bundling Verify & Resubmit →
CO-90 Ingredient Cost Adjustment fee schedule Verify & Resubmit →
CO-91 Dispensing Fee Adjustment fee schedule Review & Decide →
CO-94 Processed in Excess of Charges fee schedule Review & Decide →
CO-95 Plan Procedures Not Followed authorization Verify & Resubmit →
CO-96 Non-Covered Charges coverage Verify & Resubmit →
CO-97 Bundled Service — Not Paid Separately bundling Review & Decide →
CO-100 Payment Made to Patient/Insured other Review & Decide →
CO-101 Predetermination: Anticipated Payment other Verify & Resubmit →
CO-102 Major Medical Adjustment fee schedule Review & Decide →
CO-103 Provider Promotional Discount other Review & Decide →
CO-104 Managed Care Withhold other Review & Decide →
CO-105 Tax Withholding Amount other Review & Decide →
CO-106 Patient Payment Option Not in Effect coverage Verify & Resubmit →
CO-107 Related or Qualifying Service Not Identified information missing Resubmit →
CO-108 Rent/Purchase Guidelines Not Met other Verify & Resubmit →
CO-109 Claim Not Covered by This Payer coverage Verify & Resubmit →
CO-110 Billing Date Predates Service Date other Resubmit →
CO-111 Not Covered Unless Provider Accepts Assignment coverage Verify & Resubmit →
CO-112 Service Not Furnished Directly or Not Documented information missing Appeal →
CO-114 Procedure/Product Not FDA Approved coverage Appeal →
CO-115 Procedure Postponed, Canceled, or Delayed other Review & Decide →
CO-116 Advance Indemnification Notice Requirements Not Met other Review & Decide →
CO-117 Transportation to Nearest Facility coverage Appeal →
CO-118 ESRD Network Support Adjustment fee schedule Review & Decide →
CO-119 Benefit Maximum Reached coverage Review & Decide →
CO-121 Indemnification Adjustment other Review & Decide →
CO-122 Psychiatric Services Reduction fee schedule Review & Decide →
CO-128 Newborn Services in Mother's Allowance bundling Verify & Resubmit →
CO-129 Prior Processing Information Incorrect information missing Verify & Resubmit →
CO-130 Claim Submission Fee fee schedule Review & Decide →
CO-131 Claim-Specific Negotiated Discount fee schedule Review & Decide →
CO-132 Prearranged Demonstration Project Adjustment other Review & Decide →
CO-134 Technical Fees Removed fee schedule Verify & Resubmit →
CO-135 Interim Bills Cannot Be Processed other Verify & Resubmit →
CO-139 Contracted Funding Agreement — Subscriber Employed by Provider other Verify & Resubmit →
CO-140 Patient ID Number and Name Do Not Match information missing Resubmit →
CO-143 Portion of Payment Deferred other Review & Decide →
CO-144 Incentive Adjustment for Preferred Product/Service fee schedule Review & Decide →
CO-146 Diagnosis Code Invalid for Date of Service coding error Resubmit →
CO-147 Provider Contracted/Negotiated Rate Expired or Not on File fee schedule Verify & Resubmit →
CO-148 Incomplete or Missing Information from Another Provider information missing Verify & Resubmit →
CO-149 Lifetime Benefit Maximum Reached coverage Verify & Resubmit →
CO-150 Documentation Does Not Support Level of Service coding error Review & Decide →
CO-151 Documentation Does Not Support Service Frequency coverage Review & Decide →
CO-152 Documentation Does Not Support Length of Service coding error Review & Decide →
CO-153 Documentation Does Not Support Prescribed Dosage coding error Review & Decide →
CO-154 Documentation Does Not Support Day's Supply of Medication/Supplies coding error Verify & Resubmit →
CO-155 Patient Refused the Service/Procedure other Review & Decide →
CO-157 Service Denied — Provided Due to Act of War coverage Review & Decide →
CO-158 Service Provided Outside the United States coverage Review & Decide →
CO-159 Service Provided as Result of Terrorism coverage Verify & Resubmit →
CO-160 Benefit Exclusion — Activity-Related Injury/Illness coverage Verify & Resubmit →
CO-161 Provider Performance Bonus other Appeal →
CO-163 Attachment/Documentation Not Received information missing Resubmit →
CO-164 Attachment/Documentation Not Received Timely information missing Resubmit →
CO-166 Payer's Plan Responsibility Ended coverage Verify & Resubmit →
CO-167 Diagnosis Not Covered coverage Verify & Resubmit →
CO-169 Alternate Benefit Provided coverage Review & Decide →
CO-170 Payment Denied — Provider Type Not Eligible other Verify & Resubmit →
CO-171 Payment Denied — Provider Type in This Facility Type other Verify & Resubmit →
CO-172 Provider Specialty Adjustment coverage Appeal →
CO-173 Service/Equipment Not Prescribed by Physician authorization Verify & Resubmit →
CO-174 Service Not Prescribed Prior to Delivery authorization Verify & Resubmit →
CO-175 Incomplete Prescription information missing Verify & Resubmit →
CO-176 Prescription Not Current information missing Verify & Resubmit →
CO-177 Patient Eligibility Requirements Not Met coverage Appeal →
CO-178 Spend Down Requirements Not Met coverage Review & Decide →
CO-179 Waiting Requirements Not Met coverage Appeal →
CO-180 Residency Requirements Not Met coverage Appeal →
CO-181 Invalid Procedure Code on Date of Service coding error Resubmit →
CO-182 Invalid Procedure Modifier coding error Verify & Resubmit →
CO-183 Referring Provider Not Authorized to Refer information missing Verify & Resubmit →
CO-184 Ordering/Prescribing Provider Not Eligible information missing Verify & Resubmit →
CO-185 Rendering Provider Not Eligible to Perform Service information missing Verify & Resubmit →
CO-186 Level of Care Change Adjustment fee schedule Appeal →
CO-188 Product/Procedure Not Covered Unless FDA-Recommended coverage Appeal →
CO-189 Unlisted/NOC Code Used When Specific Code Exists coding error Verify & Resubmit →
CO-190 Payment Included in SNF Qualified Stay Allowance bundling Review & Decide →
CO-192 Non-Standard COB Adjustment Code other Review & Decide →
CO-193 Original Payment Decision Maintained other Appeal →
CO-194 Anesthesia by Operating/Assistant/Attending Physician bundling Verify & Resubmit →
CO-195 Refund Issued to Wrong Payer other Verify & Resubmit →
CO-197 Precertification/Authorization/Notification Absent authorization Verify & Resubmit →
CO-198 Precertification/Authorization Limits Exceeded authorization Appeal →
CO-199 Revenue Code / Procedure Code Mismatch coding error Resubmit →
CO-200 Expenses Incurred During Lapse in Coverage coverage Verify & Resubmit →
CO-202 Non-Covered Personal Comfort or Convenience Services coverage Review & Decide →
CO-203 Discontinued or Reduced Service other Resubmit →
CO-204 Service/Equipment/Drug Not Covered Under Benefit Plan coverage Verify & Resubmit →
CO-205 Pharmacy Discount Card Processing Fee coverage Verify & Resubmit →
CO-206 NPI Not On File With Payer information missing Verify & Resubmit →
CO-207 Invalid NPI Format information missing Resubmit →
CO-208 NPI Billing Provider Not Matched information missing Verify & Resubmit →
CO-210 Pre-Certification/Authorization Not Timely authorization Verify & Resubmit →
CO-211 NDC Not Eligible for Rebate / Not Covered coverage Verify & Resubmit →
CO-212 Administrative Surcharges Not Covered coverage Review & Decide →
CO-213 Physician Self-Referral Prohibition Violation other Appeal →
CO-215 Third Party Subrogation Settlement coverage Review & Decide →
CO-216 Review Organization Findings coverage Appeal →
CO-219 Extent of Injury Adjustment coverage Review & Decide →
CO-222 Exceeds Contracted Maximum Units fee schedule Review & Decide →
CO-223 Mandated Federal/State/Local Law Adjustment other Review & Decide →
CO-224 Patient Identity Compromised other Verify & Resubmit →
CO-225 Penalty or Interest Payment by Payer other Review & Decide →
CO-226 Provider Information Not Provided or Incomplete information missing Verify & Resubmit →
CO-227 Patient/Insured Information Not Provided information missing Verify & Resubmit →
CO-228 Information Not Provided to Previous Payer information missing Verify & Resubmit →
CO-231 Mutually Exclusive Procedures on Same Day bundling Appeal →
CO-232 Institutional Transfer DRG Difference fee schedule Verify & Resubmit →
CO-233 Hospital-Acquired Condition or Preventable Error other Appeal →
CO-234 Procedure Not Paid Separately (Bundled) bundling Resubmit →
CO-235 Sales Tax Not Reimbursable fee schedule Resubmit →
CO-236 Incompatible Procedure/Modifier Combination bundling Resubmit →
CO-237 Legislated or Regulatory Penalty other Appeal →
CO-239 Claim Spans Eligible and Ineligible Periods — Rebill coverage Resubmit →
CO-240 Diagnosis Inconsistent with Birth Weight coding error Resubmit →
CO-241 Low Income Subsidy Co-payment Adjustment patient responsibility Review & Decide →
CO-242 Services Not Provided by Network Provider coverage Review & Decide →
CO-243 Services Not Authorized by Network Provider authorization Appeal →
CO-245 Provider Performance Program Withhold fee schedule Review & Decide →
CO-246 Non-Payable Code — Required Reporting Only other Review & Decide →
CO-249 Claim Identified as Readmission other Appeal →
CO-250 Incorrect Attachment Received — Expected Document Still Missing information missing Resubmit →
CO-251 Incomplete or Deficient Attachment — Information Still Needed information missing Resubmit →
CO-252 Attachment Required to Adjudicate Claim information missing Resubmit →
CO-253 Sequestration — Medicare Federal Payment Reduction fee schedule Review & Decide →
CO-254 Dental Plan Received Claim — Benefits Not Available, Submit to Medical Plan coverage Resubmit →
CO-256 Service Not Payable Per Managed Care Contract coverage Review & Decide →
CO-258 Patient in Custody or Incarcerated — Coverage Not Available coverage Verify & Resubmit →
CO-259 Additional Payment for Dental/Vision Service Utilization coverage Review & Decide →
CO-260 Medicaid ACA Enhanced Fee Schedule Adjustment fee schedule Review & Decide →
CO-261 Procedure Inconsistent with Patient History coverage Appeal →
CO-262 Pharmaceutical Delivery Cost Adjustment fee schedule Verify & Resubmit →
CO-263 Pharmaceutical Shipping Cost Adjustment fee schedule Verify & Resubmit →
CO-264 Pharmaceutical Postage Cost Adjustment fee schedule Verify & Resubmit →
CO-265 Pharmaceutical Administrative Cost Adjustment fee schedule Verify & Resubmit →
CO-266 Pharmaceutical Compound Preparation Cost Adjustment fee schedule Verify & Resubmit →
CO-267 Claim Spans Multiple Months information missing Resubmit →
CO-268 Claim Spans Two Calendar Years other Resubmit →
CO-269 Anesthesia Not Covered for This Service coverage Appeal →
CO-270 Submit to Dental Plan Instead coverage Resubmit →
CO-272 Coverage/Program Guidelines Not Met coverage Appeal →
CO-273 Coverage/Program Guidelines Exceeded coverage Appeal →
CO-274 Fee/Service Not Payable — Care Coordination Arrangement coverage Verify & Resubmit →
CO-276 Services Denied by Prior Payer Not Covered coverage Appeal →
CO-278 Performance Program Proficiency Requirements Not Met other Verify & Resubmit →
CO-279 Services Not Provided by Preferred Network Providers coverage Verify & Resubmit →
CO-280 Claim Received but Benefits Not Covered — Submit to Pharmacy Plan coverage Resubmit →
CO-281 Deductible Waived Per Contractual Agreement fee schedule Verify & Resubmit →
CO-282 Procedure/Revenue Code Inconsistent with Type of Bill coding error Resubmit →
CO-283 Attending Provider Not Eligible to Direct Care other Verify & Resubmit →
CO-284 Authorization Valid but Not Applicable to Billed Services authorization Verify & Resubmit →
CO-285 Appeal Procedures Not Followed other Appeal →
CO-286 Appeal Time Limits Not Met timely filing Review & Decide →
CO-287 Referral Exceeded authorization Verify & Resubmit →
CO-288 Referral Absent / Missing Referral authorization Verify & Resubmit →
CO-289 Dental/Medical Plan Benefits Not Available coverage Review & Decide →
CO-290 Dental Plan Claim Forwarded to Medical Plan coverage Verify & Resubmit →
CO-291 Medical Plan Claim Forwarded to Dental Plan coverage Verify & Resubmit →
CO-292 Medical Plan Claim Forwarded to Pharmacy Plan coverage Verify & Resubmit →
CO-293 Payment Made to Employer other Review & Decide →
CO-294 Payment Made to Attorney other Review & Decide →
CO-295 Pharmacy Direct/Indirect Remuneration (DIR) Adjustment fee schedule Review & Decide →
CO-296 Precertification/Authorization Number Does Not Apply to Provider authorization Verify & Resubmit →
CO-297 Medical Plan Claim — Submit to Vision Plan coverage Verify & Resubmit →
CO-298 Medical Plan Claim Forwarded to Vision Plan coverage Verify & Resubmit →
CO-299 Billing Provider Not Eligible for Payment other Verify & Resubmit →
CO-300 Medical Plan Claim Forwarded to Behavioral Health Plan coverage Verify & Resubmit →
CO-301 Medical Plan Claim — Submit to Behavioral Health Plan coverage Verify & Resubmit →
CO-302 Authorization Time Limit Expired authorization Appeal →
CO-303 QMB Patient Responsibility Not Covered coverage Review & Decide →
CO-304 Benefits Not Available — Submit to Hearing Plan coverage Verify & Resubmit →
CO-305 Claim Forwarded to Hearing Plan coverage Verify & Resubmit →
CO-306 Type of Bill Inconsistent with Patient Status coding error Verify & Resubmit →
CO-307 Medicare Drug Price Negotiation Refund fee schedule Review & Decide →
CO-308 Contracted Funding Agreement Adjustment fee schedule Review & Decide →
CO-A0 Patient Refund Amount other Review & Decide →
CO-A1 Missing Remark Code information missing Verify & Resubmit →
CO-A5 Medicare PPS Capital Cost Outlier Amount fee schedule Review & Decide →
CO-A6 Prior Hospitalization or 30-Day Transfer Requirement Not Met coverage Appeal →
CO-A8 Ungroupable DRG coding error Verify & Resubmit →
CO-B1 Non-Covered Visits coverage Review & Decide →
CO-B10 Allowed Amount Reduced — Component Already Paid bundling Verify & Resubmit →
CO-B11 Claim Transferred to Proper Payer coverage Verify & Resubmit →
CO-B12 Services Not Documented in Medical Records information missing Appeal →
CO-B13 Previously Paid Service duplicate Review & Decide →
CO-B14 Only One Visit Per Physician Per Day Covered duplicate Verify & Resubmit →
CO-B15 Qualifying Service/Procedure Not Received bundling Verify & Resubmit →
CO-B16 New Patient Qualifications Not Met coding error Verify & Resubmit →
CO-B20 Service Furnished by Another Provider duplicate Verify & Resubmit →
CO-B22 Payment Adjusted Based on Diagnosis coding error Verify & Resubmit →
CO-B23 Procedure Not Authorized per CLIA Proficiency Test coverage Verify & Resubmit →
CO-B4 Late Filing Penalty timely filing Review & Decide →
CO-B7 Provider Not Certified/Eligible coverage Verify & Resubmit →
CO-B8 Alternative Services Not Utilized coverage Appeal →
CO-B9 Patient Enrolled in Hospice coverage Verify & Resubmit →
CO-P1 State Mandated Requirement — Property and Casualty other Verify & Resubmit →
CO-P10 Payment Reduced to Zero Pending Litigation other Review & Decide →
CO-P12 Workers' Compensation Jurisdictional Fee Schedule Adjustment fee schedule Review & Decide →
CO-P13 Workers' Compensation Jurisdictional Regulation Adjustment other Review & Decide →
CO-P14 Benefit Included in Another Same-Day Service bundling Verify & Resubmit →
CO-P15 Workers' Compensation Medical Treatment Guideline Adjustment coverage Appeal →
CO-P16 Provider Not Authorized to Treat Injured Workers authorization Verify & Resubmit →
CO-P2 Non-Work Related Injury/Illness coverage Verify & Resubmit →
CO-P4 Workers' Compensation Claim Non-Compensable coverage Verify & Resubmit →
CO-P5 Reasonable and Customary Fee Adjustment (No Legislated Maximum) fee schedule Review & Decide →
CO-P6 Benefits Entitlement Adjustment coverage Verify & Resubmit →
CO-P7 Billed Code Not in Fee Schedule/Database fee schedule Resubmit →
CO-P8 Claim Under Investigation other Review & Decide →
CO-P9 No CPT/HCPCS Code Available for Service coding error Resubmit →
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Other Group Codes

OA
Other Adjustment
PI
Payor Initiated Reduction
PR
Patient Responsibility