CurrentBlue Cross Blue Shield - OklahomaPolicy N/A

Diagnosis code guideline and related coding edits

Defines edits and validation rules for diagnosis code placement, laterality, anatomical modifiers, global surgery modifiers, and required diagnoses for specific procedures affecting professional and facility claims for Blue Cross Blue Shield - Oklahoma.

Policy Summary

PayerBlue Cross Blue Shield - Oklahoma

PolicyDiagnosis code guideline and related coding edits

Policy CodePolicy N/A

Change TypeNo material changes

Effective DateApr 1, 2022

Next Review DateN/A

Key ActionReport applicable global surgery modifiers (58, 78, 79) and append required anatomical modifiers (RT/LT/50 or specific site modifiers) when applicable.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

multipleedit modules

Z51.11/Z51.12chemo dx required

enabledExcludes1 enforcement

activelaterality validation

Diagnosis and Modifier Validation Rules

Diagnosis and modifier validation rules

Policy Summary

PayerBlue Cross Blue Shield - Oklahoma

PolicyDiagnosis code guideline and related coding edits

Policy CodePolicy N/A

Change TypeNo material changes

Effective DateApr 1, 2022

Next Review DateN/A

Key ActionReport applicable global surgery modifiers (58, 78, 79) and append required anatomical modifiers (RT/LT/50 or specific site modifiers) when applicable.

SourceLink

On This Page

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

External causes (ICD-10 V‑Y) cannot be the only diagnosis or listed as the primary/principal diagnosis; claims with only V‑Y codes will be denied.

Manifestation codes cannot be sequenced as the primary/principal or be the only diagnosis; the underlying condition must be reported first.

Secondary-only diagnosis codes must not be reported as the primary/principal or be the only diagnosis on the claim; such usage will be denied.

Sequela (7th character 'S') codes cannot be listed as the primary/principal or be the only diagnosis; the condition/nature of the sequela must be reported first.

Specified chemotherapy administration procedure codes require Z51.11 or Z51.12 as the primary/principal diagnosis; when the encounter is solely to receive chemotherapy, two diagnosis codes are required per ICD‑10 guidelines.

Evaluation and Management (E/M) service codes reported with only a Z00‑Z99 (Z) code will be denied when a preventive medicine service was also performed on the same date.

Diagnosis code combinations identified by Excludes1 (mutually exclusive) notes must not be billed together; such combinations will be denied for Professional claims.

Procedures that require anatomical modifiers must have the correct anatomical modifier appended (e.g., RT, LT, 50); missing or mismatched anatomical modifiers will cause denial of the claim line.

If a reported modifier does not match the appropriate anatomical site for the procedure code, the claim will be denied.

Laterality modifier to diagnosis mismatch: modifiers RT, LT, or 50 must correlate with the lateral diagnosis on the claim line; mismatches will be denied.

Laterality diagnosis to diagnosis mismatch: conflicting lateral diagnoses billed together on the same line (e.g., left and unspecified main bronchus codes) will deny the procedure.

Global surgical period modifier requirement: services provided during another procedure's postoperative global period must report the appropriate global surgery modifier (58, 78, 79) to identify staged, related, or unrelated procedures.

Required Codes and Modifier Rules

Required chemotherapy administration diagnosesICD-10Covered

Z51.11	Encounter for antineoplastic chemotherapy
Z51.12	Encounter for antineoplastic immunotherapy

Laterality modifiersModifier

RT	Right side modifier
LT	Left side modifier
50	Bilateral procedure modifier

Anatomical modifier requirement

RuleIf a procedure requires an anatomical modifier (e.g., RT, LT, 50) and the modifier is not appended, the claim line will deny.

Site mismatchIf a modifier is appended that does not match the appropriate anatomical site for the procedure code, the claim will be denied.

Laterality requirementWhen an anatomical modifier is necessary to differentiate right or left and is not appended, the claim will be denied.

Excludes1 pairing rule

Excludes1 enforcementDiagnosis code combinations identified by Excludes1 notes (mutually exclusive) will be denied for Professional claims when billed together.

DefinitionAn Excludes1 Note indicates the excluded code should never be used at the same time as the code or code range listed above the note (conditions that cannot occur together).

ScopeExcludes1 notes may appear under a specific code or following a section heading — when under a section heading, the note applies to all codes in that section.

Billing and Modifier Actions for Providers

Billing Rule

Report global surgery modifiers (58, 78, 79) and required anatomical modifiers

When providing a procedure during another procedure's postoperative global period, report the appropriate global surgery modifier to identify staged, related, or unrelated procedures and append required anatomical modifiers where applicable.

Report modifier 58 for staged or related procedure or service during the postoperative period.
Report modifier 78 for unplanned return to the operating/procedure room by the same physician for a related procedure during the postoperative period.
Report modifier 79 for an unrelated procedure or service by the same physician during the postoperative period.
Append required anatomical modifiers (e.g., RT, LT, 50) when a procedure requires them; missing or mismatched anatomical modifiers will cause the claim line to deny.

Key Definitions and Notes

Primary or Principal Diagnosis

DefinitionPrimary or Principal Diagnosis is the diagnosis reported in the first-listed position on a Professional claim or the principal diagnosis on a Facility claim; certain groups (e.g., external causes V-Y, manifestation, secondary, sequela) are not permitted as the primary/principal or only diagnosis.

Not acceptable as only/primaryExternal causes (ICD-10 V-Y) cannot be the only diagnosis or listed as the primary/principal diagnosis; such submissions will be denied.

Sequencing noteICD-10/CMS guidelines require proper sequencing of underlying conditions before manifestations and prohibit using codes intended only as secondary as the primary diagnosis.

Manifestation Diagnosis

DefinitionManifestation Diagnosis: a code that describes a manifestation of an underlying etiology; per ICD-10 guidelines the underlying condition must be sequenced first followed by the manifestation.

Sequencing requirementManifestation codes cannot be the primary/principal diagnosis or the only diagnosis on the claim; such submissions will be denied.

ApplicationWhen a condition has both an underlying etiology and manifestations, list the underlying condition first, then the manifestation code(s).

Excludes 1

DefinitionExcludes 1: an ICD-10-CM note indicating that the excluded code should never be used at the same time as the listed code; it denotes mutually exclusive conditions.

Practical effectWhen two diagnoses are identified as Excludes1 combinations, they must not be billed together; Professional claims with such pairs will be denied.

Location of noteExcludes1 notes appear under specific codes or section headings; when under a section heading the note applies to all codes in that section.

Laterality Modifier to Diagnosis Mismatch

DefinitionLaterality Modifier to Diagnosis Mismatch: an edit that assesses whether the procedure modifier (RT, LT, 50) correlates with the lateral diagnosis submitted on the claim line or header.

ExampleThe edit flags when modifiers RT/LT/50 do not correlate with the submitted diagnosis laterality — e.g., a procedure billed with RT modifier but diagnosis indicates left side or unspecified.

ResultWhen modifier and diagnosis laterality do not match, the claim line will be edited/denied per the laterality validation rules.

Laterality Diagnosis to Diagnosis Mismatch

DefinitionLaterality Diagnosis to Diagnosis Mismatch: an edit that denies procedures when two diagnoses on the same line conflict in laterality (e.g., left and unspecified main bronchus codes billed together).

ExampleExample edit: C34.01 (malignant neoplasm of left main bronchus) and C34.00 (malignant neoplasm of unspecified main bronchus) billed on the same line will be denied.

ApplicationTwo conflicting lateral diagnoses on a single procedure line constitute mismatched laterality and will result in denial of the procedure line.