CO : Contractual Obligations denial code list

MCR - 835 Denial Code List  

CO : Contractual Obligations - Denial based on the contract and as per the fee schedule amount.

CO should be sent if the adjustment is related to the contracted and/or negotiated rate Provider’s charge either exceeded contracted or negotiated agreement (rate, maximum number of hours, days or units) with the payer, exceeded the reasonable and customary amount for the rendered service(s). Use this category when a joint payer/payee agreement or a regulatory requirement  has resulted in an adjustment that the member is not responsible for, or the provider’s charge exceeds the
reasonable and customary amount and for which the  patient is responsible.

CO (Contractual Obligation) assigns financial responsibility to the provider. When CO is used to describe an adjustment, a provider is not permitted to bill the beneficiary for the amount of that adjustment; or PR (Patient Responsibility) assigns financial responsibility to the patient. Medicare beneficiaries may be billed only when Group Code PR is used with an adjustment.


For CO denial code, We could not bill the patient but we could resubmit the claim with necessary correction according to Denial.

SOME IMPORTANT CO DENIAL CODES

Denial code CO 4 says that the code for the procedure is inconsistent along with the modifier used or that a necessary modifier is supposedly missing. Denial code CO 11 says that the diagnosis may be inconsistent with the involved procedure. Denial code CO 16 says that the service or claim lacks the necessary information needed for the adjudication. The denial code CO 18 revolves around a duplicate service or claim while the denial code CO 22 revolves around the fact that the care can be covered by any other payer for coordination of the benefits involved.


The denial code CO 24 describes that the charges may be covered under a managed care plan or a capitation agreement. The denial code CO 27 revolves around the expenses that are incurred after the coverage is terminated. The denial code CO 50 is about the non-covered services as these are not deemed a medical necessity by the concerned payer. The denial code CO 96 revolves around non-covered charges while the denial code CO 97 is about service and its benefit, whether or not it is included with the allowance or payment for any other service or any other procedure which has been already adjudicated. The denial code CO 109 deals with a service or claim that is not covered

CO - Denial code full list

CO 15 Payment adjusted because the submitted authorization number is missing, invalid, or does not apply to the billed services or provider.

CO 22 Payment adjusted because this care may be covered by another payer per coordination of benefits.

CO 24 Payment for charges adjusted. Charges are covered under a capitation agreement/managed care plan.

CO 29 The time limit for filing has expired.

CO 38 Services not provided or authorized by designated (network/primary care) providers.

CO 39 Services denied at the time authorization/pre-certification was requested.

CO 45 Charges exceed your contracted/ legislated fee arrangement. This change to be effective 6/1/07: Charge exceeds fee schedule/maximum allowable or contracted/legislated fee arrangement. (Use Group Codes PR or CO depending upon liability).

CO 49 These are non-covered services because this is a routine exam or screening procedure done in conjunction with a routine exam.

CO 50 These are non-covered services because this is not deemed a `medical necessity' by the payer.

CO 51 These are non-covered services because this is a pre-existing condition

CO 54 Multiple physicians/assistants are not covered in this case .

CO 55 Claim/service denied because procedure/treatment is deemed experimental/investigational by the payer.

CO 56 Claim/service denied because procedure/treatment has not been deemed `proven to be effective' by the payer.

CO 58 Payment adjusted because treatment was deemed by the payer to have been rendered in an inappropriate or invalid place of service.

CO 60 Charges for outpatient services with this proximity to inpatient services are not covered.

CO 66 Blood Deductible.

CO 69 Day outlier amount.

CO 70 Cost outlier - Adjustment to compensate for additional costs.

CO 76 Disproportionate Share Adjustment.

CO 78 Non-Covered days/Room charge adjustment.

CO 89 Professional fees removed from charges.

CO 91 Dispensing fee adjustment.

CO 94 Processed in Excess of charges.

CO 96 Non-covered charge(s). At least one Remark Code must be provided (may be comprised of either the Remittance Advice Remark Code or NCPDP Reject Reason Code.)

CO 101 Predetermination: anticipated payment upon completion of services or claim adjudication.

CO 102 Major Medical Adjustment.

CO 103 Provider promotional discount (e.g., Senior citizen discount).

CO 107 Claim/service adjusted because the related or qualifying claim/service was not identified on this claim.

CO 110 Billing date predates service date.

CO 111 Not covered unless the provider accepts assignment.

CO 114 Procedure/product not approved by the Food and Drug Administration.

CO 117 Payment adjusted because transportation is only covered to the closest facility that can provide the necessary care.

CO 119 Benefit maximum for this time period or occurrence has been reached.

CO 125 Payment adjusted due to a submission/billing error(s). At least one Remark Code must be provided (may be comprised of either the Remittance Advice Remark Code or NCPDP Reject Reason Code.)

CO 128 Newborn's services are covered in the mother's Allowance.

CO 135 Claim denied. Interim bills cannot be processed.

CO 138 Claim/service denied. Appeal procedures not followed or time limits not met.

CO 139 Contracted funding agreement - Subscriber is employed by the provider of services.

CO 146 Payment denied because the diagnosis was invalid for the date(s) of service reported.

CO 157 Payment denied/reduced because service/procedure was provided as a result of an act of war.

CO 158 Payment denied/reduced because the service/procedure was provided outside of the United States.

CO 159 Payment denied/reduced because the service/procedure was provided as a result of terrorism.

CO 160 Payment denied/reduced because injury/illness was the result of an activity that is a benefit exclusion.

CO 162 State-mandated Requirement for Property and Casualty, see Claim Payment Remarks Code for specific explanation.

CO 165 Payment denied /reduced for absence of, or exceeded referral

CO 167 This (these) diagnosis(es) is (are) not covered.

CO 170 Payment is denied when performed/billed by this type of provider.

CO 171 Payment is denied when performed/billed by this type of provider in this type of facility.

CO 172 Payment is adjusted when performed/billed by a provider of this specialty

CO 174 Payment denied because this service was not prescribed prior to delivery

CO 175 Payment denied because the prescription is incomplete

CO 176 Payment denied because the prescription is not current

CO 183 The referring provider is not eligible to refer the service billed.

CO 184 The prescribing/ordering provider is not eligible to prescribe/order the service billed.

CO 185 The rendering provider is not eligible to perform the service billed.

CO 188 This product/procedure is only covered when used according to FDA recommendations.

CO 190 Payment is included in the allowance for a Skilled Nursing Facility (SNF) qualified stay.

CO 191 Claim denied because this is not a work related injury/illness and thus not the liability of the workers’ compensation carrier.

CO 193 Original payment decision is being maintained. This claim was processed properly the first time.

CO 205 Pharmacy discount card processing fee

CO 211 National Drug Codes (NDC) not eligible for rebate, are not covered.

CO A4 Medicare Claim PPS Capital Day Outlier Amount.

CO A5 Medicare Claim PPS Capital Cost Outlier Amount.

CO A7 Presumptive Payment Adjustment

CO B10 Allowed amount has been reduced because a component of the basic procedure/test was paid. The beneficiary is not liable for more than the charge limit for the basic procedure/test.

CO B14 Payment denied because only one visit or consultation per physician per day is covered.

CO B16 Payment adjusted because `New Patient' qualifications were not met.

CO B23 Payment denied because this provider has failed an aspect of a proficiency testing program.

CO B4 Late filing penalty.

CO B5 Payment adjusted because coverage/program guidelines were not met or were exceeded.

CO B7 This provider was not certified/eligible to be paid for this procedure/service on this date of service. CO denial code list BCBS insurance ADJUSTMENT GROUP CODE ADJUSTMENT REASON CODE  REMITTANCE MESSAGE CO 6 Services not covered due to patient age CO 7 Services not covered due to patient sex CO 8 Provider specialty not covered for this service CO 9 Member's age not compatible with this diagnosis CO 10 Services not covered due to sex restrictions CO 10 Patient's sex no allowed for this diagnosis CO 11 Procedure not covered with this diagnosis CO 18 Duplicate of a service previously submitted CO 20 Claim denied due to third party liability CO 24 Capitated line item CO 27 Patient has been terminated CO 27 Plan terminated or not in effect on date of service CO 27 Group terminated or not in effect on date of service CO 27 Subscriber or patient terminated or not in effect CO 27 Date of service not within effective dated range CO 29 Claim was not received within the filing limit CO 30 Patient waiting period has not expired CO 30 Diagnosis waiting period has not expired CO 32 Dependent children over age or not students are not covered CO 35 Member met or exceeded maximum dollar amount allowed CO 35 Maximum benefits paid for this diagnosis CO 35 Major Medical Lifetime Maximum met CO 35 Major Medical Lifetime Maximum met CO 38 Primary Care Physician did not approve these services CO 40 Out-of-plan services not covered for emergencies CO 47 Services not covered with this diagnosis CO 47 Diagnosis not allowed CO 47 Special processing claim CO 52 Disallowed out of plan referrals are not covered CO 57 Non-payment is a result of utilization review decision CO 61 Proper second opinion was not obtained CO 62 Limit on number of units/visits on authorization exceeded CO 62 Dollar limit on authorization is exceeded CO 62 Penalty applied - No precertification CO 78 Inpatient services are denied for this stay CO 95 Penalty applied to line CO 96 Service is not covered CO 96 Not a covered benefit for this member CO 96 Not a covered benefit for this type of employee CO 97 Procedure is incident to CO 97 Procedure part of lab panel CO 97 No fee schedule for this line item CO 97 Line XXX denied due to starred procedure rule CO 97 Procedure is mutually exclusive to CO 97 Procedure is being rebundled to CO 97 Procedure is included in CO 97 Denied service rendered within pre-op days CO 97 Denied service rendered within post-op days CO 119 Member met or exceeded maximum number of services allowed CO 141 Services occurs between two period counts CO 141 Some or all services did not meet eligibility requirement CO A1 Not covered by BlueCare Family Plan CO A1 Claim not eligible for payment CO A1 Denied - multiple component billing CO A2 Procedure covered only in the case of an accident CO A2 Procedure covered only in emergency (urgent) case CO A2 Second surgical opinion paid at reduced rate CO A2 Denied - Smart suspense CO B1 Service(s) covered only under an accident rider CO B5 BlueCare Family Plan guidelines not followed CO B5 Charges applied toward penalty CO B15 Follow-up visits included in the global surgery fee CO B18 Procedure has been terminated on the plan CO B18 Invalid procedure code - please submit with the correct code CO B22 Diagnosis must be severe for this service to be covered