Blue Cross Blue Shield TN CRP ESR Coverage Update

inv-01: Covered indications

Covered when the following conditions apply based on diagnosed or suspected inflammatory condition

Covered indications list: Measurement of ESR and/or CRP meets coverage criteria for inflammatory conditions as specified in the policy reimbursement table (examples include rheumatoid arthritis, polymyalgia rheumatica, giant cell arteritis, systemic lupus erythematosus, ankylosing spondylitis, periprosthetic joint infection, acute hematogenous osteomyelitis, Hodgkin lymphoma, urticaria, hypereosinophilic syndrome).

See reimbursement table for per-condition test preference and frequency.

inv-02: Not covered: screening without findings

Not covered

Unacceptable use: Measurement of CRP and/or ESR during a general exam without abnormal findings.

This use does not meet coverage criteria.

inv-03: First-line testing

Coverage and preferred testing approach when evaluating suspected infection or inflammation

Preferred first-line test for acute inflammation/infection: Order CRP as the first-line inflammatory marker when evaluating suspected acute infection or acute-phase inflammation because CRP demonstrates superior early sensitivity and higher overall AUC compared with ESR in large cohort analyses.

Testing both markers simultaneously generally does not meaningfully increase diagnostic accuracy; avoid routine dual-marker ordering without clinical justification (Watson et al.).

inv-04: PJI evaluation

When assessing possible periprosthetic joint infection (PJI)

Use of ESR and/or CRP in PJI diagnosis: CRP and ESR may be used as supportive biomarkers for suspected PJI and are included as minor criteria in consensus definitions; CRP typically shows higher diagnostic odds ratio than ESR but both can produce false negatives, especially with low‑virulence organisms.ESR 10 mm/h; CRP 5 mg/L (sensitivity-optimized cutoffs reported to achieve ≥95% sensitivity in some series)

Interpret results within composite scoring systems (eg, MSIS point system) and consider additional tests (eg, IL‑6, cultures, imaging) as indicated.

inv-05: Hodgkin lymphoma

Oncologic indications where ESR is used for staging and management

Hodgkin lymphoma staging and follow-up: ESR is an essential test in staging classical Hodgkin lymphoma and influences treatment algorithms (including radiation dosing); an ESR ≥50 mm/h is considered an early-stage unfavorable factor and should be documented within 6 months of diagnosis and during follow-up per NCCN guidance.ESR >= 50 mm/h

Follow NCCN-recommended surveillance intervals (eg, every 3–6 months for 1–2 years, then less frequently).

inv-06: Castleman disease

Castleman disease diagnostic criteria

Minor diagnostic criteria for idiopathic MCD: Elevation of CRP (>10 mg/L) is mandatory for idiopathic multicentric Castleman disease and tracking CRP is highly recommended; ESR (>15 mm/h) is acceptable if CRP is unavailable.CRP >10 mg/L or ESR >15 mm/h

Document CRP when used in the diagnostic workup per NCCN.

inv-07: Rheumatology monitoring

Rheumatologic disease monitoring

Use of ESR/CRP in PMR and RA management: Guidelines recommend baseline and serial monitoring of CRP and/or ESR for polymyalgia rheumatica and rheumatoid arthritis; these markers are incorporated into validated composite disease activity indices (eg, DAS28, SDAI, CDAI) and should be measured at recommended intervals during active disease (commonly every 1–3 months) until treatment targets are achieved.

ACR/EULAR guidance supports inclusion of acute-phase reactants in composite scores; frequency should follow guideline and clinical context.

inv-08: Guideline-aligned clinical indications for CRP/ESR testing

Summarized situations where CRP and/or ESR testing is recommended by guideline bodies

Rheumatoid arthritis monitoring: Use validated composite scores (eg, DAS28, SDAI, CDAI, RAPID3) that may include CRP or ESR; in recent-onset active RA measure CRP and disease activity monthly until controlled, then less frequently per guidelines.

References include EULAR, ACR, NCC-CC, CRA, RACGP.

Giant cell arteritis / Polymyalgia rheumatica: At baseline test CRP and/or ESR (many guidelines recommend both) and monitor inflammatory markers at each clinic visit or every 3 months during active steroid therapy; when initiating glucocorticoids for suspected GCA, obtain labs before or immediately after the first dose.

References include BSR/BHPR, AAFP, EULAR/ACR.

Prosthetic joint infection (PJI) evaluation: Include ESR and CRP as part of composite diagnostic criteria (eg, MSIS); elevated CRP or D-dimer and elevated ESR contribute to point-based definitions but neither marker alone is definitive.MSIS scoring (≥6 suggests infection)

inv-09: Reference citations

No explicit coverage criteria are present in these chunks; this section provides references and supports the broader policy.

References only: This section lists supporting literature and guideline sources (eg, EULAR, ACR, BSR, NCCN, MSIS, PIDS/IDSA, WHO, FDA) relevant to the use of CRP and ESR in diagnosis and monitoring of inflammatory conditions.

See reference list for individual citations.

Measurement of C‑reactive protein (CRP) and/or erythrocyte sedimentation rate (ESR) performed as part of a general examination when there are no abnormal findings does not meet coverage criteria and is excluded from coverage. This use is explicitly identified as an unacceptable screening indication and is considered not medically necessary in the absence of a diagnosed or suspected inflammatory condition.

Routine simultaneous ordering of ESR and CRP for undifferentiated complaints without clinical justification is discouraged. Large cohort evidence shows testing both markers together provides negligible improvement in diagnostic accuracy (adding ESR to CRP changed AUC from 0.682 to 0.688), and professional guidance (ASCP Choosing Wisely) recommends preferring CRP for acute-phase evaluation, so duplicate default ordering may be unnecessary and can risk denial if not documented.

Routine laboratory panels that include ESR have limited value for surveillance to detect Hodgkin lymphoma relapse. The American College of Radiology notes limited data supporting routine blood tests for relapse detection and indicates most recurrences are identified by history and physical exam; reliance on ESR alone as sole surveillance is therefore not supported.

CRP and ESR can be elevated after surgery for reasons unrelated to infection; guideline statements for periprosthetic joint infection caution that these markers may be non‑specific postoperatively. This limitation should be recognized when interpreting CRP/ESR results in the post‑surgical setting and when using them to diagnose PJI.

The reviewed reference material and citation lists do not specify additional explicit test exclusions beyond those stated elsewhere in the policy. Supporting literature is provided for clinical context but does not add further standalone exclusions.

Routine measurement of CRP and/or ESR as part of a general medical examination when no clinical abnormality or suspected inflammatory condition is present is considered not medically necessary and does not meet coverage criteria. Testing must be associated with an appropriate diagnosis or clinical indication to qualify for coverage.

Ordering both ESR and CRP together by default in the evaluation of undifferentiated inflammation is not supported by evidence of meaningful incremental diagnostic yield. Cohort data demonstrate minimal AUC improvement when both tests are ordered and professional guidance favors CRP for acute‑phase detection; therefore simultaneous routine ordering without documented rationale is discouraged.

Using ESR or CRP alone as the sole surveillance method to detect Hodgkin lymphoma relapse is generally not supported because available data are limited and most recurrences are identified by history and physical exam. ESR may be part of follow‑up when elevated at diagnosis, but reliance on a single inflammatory marker for surveillance is not recommended.

The cited reference lists and supporting materials included in the policy do not contain additional explicit not‑medically‑necessary statements beyond those summarized in the policy text. The bibliography provides context and sources for the guidance above.

Indications and Condition-Specific Guidance

inv-56: Inflammatory and rheumatologic conditions (e.g., RA, PMR, GCA, ankylosing spondylitis, polymyalgia rheumatica), infections (e.g., septic joints), select malignancies (e.g., Hodgkin lymphoma), periprosthetic joint infections, and monitoring disease activity.

Inflammatory and rheumatologic conditions (examples)

Supported conditions: CRP and/or ESR testing is covered for inflammatory and rheumatologic conditions including rheumatoid arthritis, polymyalgia rheumatica, giant cell arteritis, ankylosing spondylitis, systemic lupus erythematosus, periprosthetic joint infection, acute hematogenous osteomyelitis, Hodgkin lymphoma, urticaria, and hypereosinophilic syndrome.

Per-condition test preference and suggested frequency are provided in the reimbursement table.

inv-57: Evaluation of suspected periprosthetic joint infection or prosthetic joint revision — CRP and ESR can be used as supportive diagnostic markers; consider lower cutoffs for higher sensitivity and recognize potential false neg...

Evaluation of suspected periprosthetic joint infection or prosthetic joint revision

PJI supportive markers: CRP and ESR may be used as supportive diagnostic markers for suspected PJI; CRP commonly has higher diagnostic odds ratio, both markers can be falsely negative particularly with low-virulence organisms, and lowering cutoffs (eg, ESR 10 mm/h, CRP 5 mg/L) has been reported to increase sensitivity in select studies.ESR 10 mm/h; CRP 5 mg/L for sensitivity-optimized screening in some series

Interpret in context of composite definitions (MSIS) and adjunctive tests (cultures, IL‑6, imaging).

inv-58: Staging and follow-up of Classical Hodgkin Lymphoma — ESR is essential in staging and influences treatment algorithm and radiation dosing per NCCN.

Staging and follow-up of Classical Hodgkin Lymphoma

ESR in Hodgkin lymphoma: ESR is essential for staging classical Hodgkin lymphoma and influences treatment decisions and radiation dosing; an ESR ≥50 mm/h is considered an early-stage unfavorable factor and should be documented near diagnosis and during follow-up per NCCN guidance.ESR >=50 mm/h

Follow NCCN-recommended surveillance schedule for frequency of testing.

inv-59: Workup and monitoring of Castleman disease and polymyalgia rheumatica — CRP is mandatory for idiopathic MCD diagnosis; CRP and/or ESR included in PMR baseline and monitoring labs per EULAR/ACR guidance.

Workup and monitoring of Castleman disease and polymyalgia rheumatica

Castleman disease: For idiopathic multicentric Castleman disease, elevation of CRP (>10 mg/L) is mandatory for diagnosis and tracking CRP is highly recommended; ESR (>15 mm/h) may be accepted if CRP is not available.CRP >10 mg/L or ESR >15 mm/h

Document CRP values when used in diagnostic workup per NCCN.

PMR baseline and monitoring: In polymyalgia rheumatica, obtain baseline CRP and/or ESR prior to initiating therapy and monitor CRP and/or ESR during follow-up (eg, every 3 months during long-term steroid therapy) as recommended by EULAR/ACR and BSR/BHPR.

When initiating glucocorticoids for suspected GCA, obtain labs before or immediately after first dose.

inv-60: Evaluation of infection vs autoimmune disease — CRP has marginally superior diagnostic accuracy for infections and equivalent performance for autoimmune conditions; preferentially order...

Evaluation of infection vs autoimmune disease

CRP vs ESR for infection: CRP demonstrates marginally superior diagnostic accuracy compared with ESR for infections and has a higher AUC in large cohort studies; CRP is therefore preferred as the first-line marker when infection is suspected.

Measuring both markers simultaneously rarely improves diagnostic yield and is discouraged without a clinical rationale.

inv-61: Rheumatoid arthritis monitoring and disease activity assessment — Measure CRP and components of disease activity regularly; monthly monitoring in recent-onset active RA until controlled, then frequency b...

Rheumatoid arthritis monitoring and disease activity assessment

RA monitoring: Measure CRP and components of validated disease activity instruments (eg, DAS28, SDAI, CDAI) regularly; in recent-onset active RA measure CRP and disease activity monthly until controlled, then adjust monitoring frequency based on disease status (commonly every 1–3 months during active disease).

CRP or ESR may be used within composite scores; EULAR and ACR guidance provide recommended intervals and use cases.

inv-62: Giant cell arteritis and polymyalgia rheumatica diagnosis and monitoring — Test CRP and ESR at baseline; monitor at each clinic visit or every 3 months during active therapy per guidelines.

Giant cell arteritis and polymyalgia rheumatica diagnosis and monitoring

GCA/PMR testing and follow-up: Test CRP and ESR at baseline for suspected GCA/PMR and monitor inflammatory markers at each clinic visit or every 3 months during active steroid therapy; when starting glucocorticoids for suspected GCA obtain blood for full blood count, CRP and ESR before or immediately after the first dose.

Many guidelines recommend testing both markers; interpret results in the full clinical context.

inv-63: Evaluation for prosthetic joint infection — ESR and CRP used as part of composite diagnostic criteria; supportive but not definitive.

Evaluation for prosthetic joint infection

ESR/CRP as part of composite criteria: ESR and CRP are included as supportive minor criteria in PJI diagnostic frameworks and contribute to composite/point-based definitions (eg, MSIS); neither marker alone is definitive for PJI diagnosis.MSIS point scoring (≥6 suggests infection)

Guidelines caution that markers may be elevated for unrelated reasons after surgery and recommend interpretation alongside clinical, microbiologic, and imaging data.

inv-64: Pediatric acute hematogenous osteomyelitis initial evaluation — Obtain baseline serum CRP for sequential monitoring; ESR not routinely used.

Pediatric acute hematogenous osteomyelitis initial evaluation

Pediatric AHO baseline CRP: Obtain a baseline serum CRP on initial evaluation for suspected pediatric acute hematogenous osteomyelitis to serve as the reference for sequential monitoring; ESR is not routinely used for diagnosis in children per PIDS/IDSA guidance.

Do not use procalcitonin as a routine diagnostic test for AHO in children per guideline.

inv-65: Multiple conditions supported by society recommendations — Rheumatoid arthritis, polymyalgia rheumatica, giant cell arteritis, ankylosing spondylitis, periprosthetic joint infection, acute hematogenous osteomyelitis, systemic lupus erythematosus, Hodgkin lymphoma, urticaria, hypereosinophilic syndrome

Various professional society recommendations summarize CRP and/or ESR use

Society-supported indications: Multiple professional societies (EULAR, ACR, BSR/BHPR, MSIS, AAOS, PIDS/IDSA, NCCN, CRA, RACGP, etc.) support the use of CRP and/or ESR for initial assessment and monitoring in conditions including RA, PMR, GCA, ankylosing spondylitis, PJI, AHO, SLE, and Hodgkin lymphoma, with specifics varying by guideline.

Refer to individual guideline recommendations for test preference and monitoring frequency per condition.

inv-66: Use of CRP, hsCRP, and ESR in diagnosis and monitoring of rheumatologic conditions and assessment of infection/inflammation.

Use of CRP, hsCRP, and ESR in diagnosis and monitoring

Test roles and variants: CRP (including high-sensitivity and cardiac assay variants) and ESR are used across rheumatologic conditions and for assessment of infection/inflammation; CRP rises and falls more rapidly than ESR, making it preferable for early and serial monitoring in many contexts.

Assay selection and interpretation should follow laboratory standards and guideline recommendations (FDA and ICSH/ISCH referenced).

Recommended Monitoring Frequency

inv-67: CRP and/or ESR — Frequency examples

General ruleFrequency varies by condition; follow the per-condition guidance in the reimbursement table (examples below).

Rheumatoid arthritis (active)Measure every 1–3 months initially until treatment target achieved, then 6–12 months once stable.

Hodgkin lymphomaEvery 3–6 months for 1–2 years, then every 6–12 months for the next 3 years, then annually.

Polymyalgia rheumatica (on long‑term steroid therapy)At diagnosis and every 3 months during long‑term steroid therapy.

inv-68: ESR and/or CRP (composite disease activity monitoring)

Recommended interval1–3 months while monitoring disease activity using composite measures (eg, DAS28/SDAI/CDAI).

ContextApplied as part of composite disease activity monitoring in rheumatoid arthritis and similar conditions.

AdjustmentFrequency should be individualized based on disease activity and response to therapy.

inv-69: ESR schedule for Hodgkin lymphoma follow-up

NCCN follow-up scheduleWhen ESR was elevated at diagnosis: every 3–6 months for 1–2 years; then every 6–12 months for the next 3 years; then annually.

DocumentationESR should be tested within 6 months of diagnosis and used in staging and treatment decisions per NCCN.

RoleESR influences treatment algorithms and involved-site radiation dosing in Hodgkin lymphoma.

inv-70: CRP (and composite disease activity testing) — Frequency

Recommended frequency (RA)CRP and composite disease activity measures: monthly to every 1–3 months during active disease until control is achieved.

SLE contextCRP tested at initial diagnosis and every 1–3 months during active disease; every 6–12 months when stable.

Use casePreferred for tracking acute changes and infections due to rapid rise and fall compared with ESR.

inv-71: ESR or CRP — Every 3 months

PMR monitoring on steroidsMeasure ESR or CRP every 3 months during active steroid therapy and at each clinic visit per BSR/AAFP guidance.

GCA baseline/follow-upObtain CRP and ESR at or near diagnosis and during follow‑up visits; include in routine follow-up labs.

General guidanceUse ESR or CRP at regular intervals to support clinical assessment; frequency tied to clinical visits and disease activity.

inv-72: ESR (in some variants) — 1–2 times per year

ACR follow-up variants (Hodgkin)In several ACR follow-up variants, ESR was conducted 1–2 times per year (some variants rated as not usually appropriate to appropriate).

Limited value noteACR notes limited data for routine blood work to detect relapse; many recurrences detected by history and exam.

Use implicationAnnual or biannual ESR may be used in some follow-up variants but should not be sole surveillance method.

inv-73: CRP and/or ESR — Condition-dependent frequencies

Frequency varies by conditionTesting intervals depend on the indication: examples include monthly testing during active RA until controlled, every 1–3 months during active SLE, and condition‑dependent schedules for GCA/PMR and PJI.

Follow guidelinesUse specialty guideline recommendations (EULAR, ACR, NCCN, MSIS) to determine specific monitoring intervals.

IndividualizeAdjust frequency based on clinical status, treatment response, and intended use (diagnosis vs monitoring).

inv-74: (no content)

Procedure Codes and Numeric Thresholds

No codes listed

No codes listed in this sectionmixed

No codes listed

inv-21: ESR threshold for Hodgkin lymphoma

Hodgkin lymphoma ESR thresholdESR ≥50 mm/h is considered an early‑stage unfavorable factor and influences staging and treatment algorithms.

Clinical impactAn ESR <50 versus ≥50 can determine choice of NCCN algorithm and radiation dosing decisions.

SourceNCCN guidance cited in policy documentation.

inv-22: PJI sensitivity-optimized cutoffs

PJI sensitivity-optimized cutoffsESR 10 mm/h and CRP 5 mg/L achieve ≥95% sensitivity in one study (Bingham et al., 2019); combined cutoffs yielded 100% sensitivity in that cohort.

Note on standard cutoffsStandard MSIS cutoffs (ESR 30 mm/h, CRP 10 mg/L) may yield lower sensitivity and higher false positives per authors.

Clinical implicationLowering cutoffs can improve sensitivity for ruling out PJI but may increase false positives.

inv-23: Castleman minor diagnostic criteria

Castleman minor diagnostic criteriaElevated CRP (>10 mg/L) is mandatory; ESR >15 mm/h is acceptable if CRP unavailable.

RecommendationTracking CRP levels is highly recommended for idiopathic multicentric Castleman disease.

NCCN statusNCCN lists LDH, CRP, and ESR as 'essential' laboratory tests in workup; CRP is emphasized for diagnosis.

inv-24: Hodgkin lymphoma unfavorable factor

Unfavorable factor thresholdESR ≥50 mm/h is considered an unfavorable (early‑stage) factor in Hodgkin lymphoma staging.

Treatment implicationsAn ESR ≥50 may lead to a different NCCN algorithm (eg, HODG‑6) with consideration of involved‑site radiation therapy.

Testing timingESR should be documented within 6 months of diagnosis per NCCN recommendations.

inv-25: Tier 1 trigger for MIS-C (example threshold)

MIS-C tier 1 trigger exampleCRP ≥5 mg/L or ESR ≥40 mm/hr plus one suggestive lab feature (eg, neutrophilia or platelet <150,000/µL) prompts tier 2 testing per ACR pediatric guidance.

Follow-up actionsTier 2 testing includes EKG and echocardiogram when tier 1 thresholds met with suggestive features.

ContextPart of ACR two‑tier algorithm for suspected multisystem inflammatory syndrome in children (MIS‑C).

inv-26: MSIS PJI point values

MSIS PJI point valuesElevated CRP or D‑dimer = 2 points; elevated ESR = 1 point; a total ≥6 points indicates infection per MSIS 2018 criteria.

Role of markersCRP and ESR are minor/pointed contributors to composite PJI scoring and are supportive but not definitive alone.

Clinical useUse in conjunction with other microbiologic and clinical criteria for PJI diagnosis.

inv-27: No numeric laboratory thresholds present (general note)

No numeric thresholdsFor many indications the policy provides no single numeric laboratory threshold; thresholds are condition‑specific or referenced to guideline values.

Interpretation adviceRefer to condition‑specific guidance (eg, NCCN, MSIS, EULAR) for numeric cutoffs when used in diagnostic algorithms.

ExamplesSee Hodgkin ESR ≥50, PJI optimized cutoffs (ESR 10/CRP 5), Castleman CRP >10/ESR >15 for specific contexts.

Provider Actions, Documentation, and Prior Authorization

Documentation Required

Diagnosis required

Coverage determination depends on the diagnosed or suspected inflammatory condition; specify the diagnosis to support ESR and/or CRP testing. Measurement of ESR and/or CRP MEETS COVERAGE CRITERIA for inflammatory conditions as detailed elsewhere in this policy. Measurement of CRP and/or ESR during a general exam without abnormal findings does not meet coverage criteria.

Diagnosis must be documented on the request/claim to support medical necessity.

Documentation Required

When starting glucocorticoids for suspected GCA

When starting glucocorticoids for suspected giant cell arteritis (GCA), document relevant symptoms and signs and obtain blood for full blood count, CRP, and ESR before or immediately after commencing high-dose glucocorticoids. If GCA is strongly suspected, the first dose may be given without waiting for laboratory results; however the laboratory draw should occur as soon as possible.

Document symptoms/signs, timing of steroid initiation, and lab draw time relative to first dose.

Documentation Required

Monitoring frequency for PMR on therapy

For polymyalgia rheumatica (PMR), obtain ESR and/or CRP at initial diagnosis and monitor either ESR or CRP every three months during long-term steroid therapy.

Monitoring frequency: every 3 months while on long-term steroid therapy.

Billing Rule

Avoid simultaneous dual-marker testing without justification

Avoid routinely ordering both ESR and CRP simultaneously without clinical justification; evidence shows limited incremental diagnostic value when both markers are measured together for most indications.

Order CRP as first-line test for acute phase inflammation unless specific indication exists for ESR.
Document clinical rationale when both CRP and ESR are ordered together.

Denial Risk

Routine blood work (including ESR) has limited utility for relapse detection in Hodgkin lymphoma

Routine blood work (including ESR) has limited data for detecting relapses in Hodgkin lymphoma; most recurrences are detected by history and physical exam rather than routine imaging or blood tests.

If ESR is used in follow-up of Hodgkin lymphoma, follow guideline-recommended intervals and document rationale.
Routine ordering of ESR as relapse surveillance should be justified by clinical context.

Documentation Required

Lab certification/documentation

Testing of serum acute phase reactants (CRP) and ESR must be performed in laboratories meeting Clinical Laboratory Improvement Amendments (CLIA) quality standards. Laboratory-developed tests (LDTs) remain subject to CLIA regulation and must be validated and documented by the performing laboratory.

Ensure testing laboratory CLIA certification is documented in lab reports.
Document assay type (conventional CRP, hsCRP, cCRP) when relevant to interpretation.

Prior Authorization

Prior authorization for listed CPT codes

Procedure codes 85651, 85652 (ESR non-automated and automated) and 86140 (CRP) are referenced for billing. Follow payer prior authorization requirements for these CPT codes if applicable under the member's benefit plan.

Affected CPT codes: 85651, 85652, 86140.
Check member-specific benefit plan for prior authorization rules; obtain prior auth when required by the plan before performing testing.

Note

Government policy precedence

If there is a conflict between this policy and any relevant government policy (e.g., Local Coverage Determinations (LCDs), National Coverage Determinations (NCDs), or state Medicaid), the applicable government policy takes precedence. Consult CMS and state Medicaid resources for the most up-to-date coverage rules.

Medicare LCD/NCD and state Medicaid policies override this policy when applicable.
CMS search: https://www.cms.gov/medicare-coverage-database/search.aspx

Note

Effective date and adoption note

Effective Date: 2023-07-01. Adopted Avalon policy recommendation.

Policy effective date: 7/1/2023

Ordering and Laboratory Requirements

Billing Rule

Order tests only with an appropriate inflammatory diagnosis

Ordering must be associated with an appropriate diagnosed or suspected inflammatory condition to meet coverage criteria; tests ordered without an appropriate diagnosis (e.g., routine general exam) do not meet coverage.

Coverage depends on the diagnosed or suspected inflammatory condition (Note 1).
Ordering requirement: tests must be associated with an appropriate diagnosis to meet coverage criteria.

Billing Rule

No provider-type restrictions for ordering specified

The policy does not impose explicit restrictions on which provider types may order ESR or CRP; guideline recommendations reference both primary care and specialty settings for baseline and monitoring tests.

Documentation Required

Order baseline and follow-up CRP/ESR and document symptoms when starting treatment for suspected GCA

When initiating therapy for suspected giant cell arteritis, order baseline and follow-up CRP and/or ESR and document the patient's symptoms and signs as expected by guideline-based recommendations.

BSR: obtain blood for full blood count, CRP and ESR before or immediately after commencing high‑dose glucocorticoids.
Document diagnostically relevant symptoms and signs when starting glucocorticoids for suspected GCA.

Billing Rule

Order tests per government/local coverage and use CLIA‑compliant labs

Ensure tests are ordered consistent with applicable government/local coverage determinations and that testing is performed in CLIA‑compliant laboratories as documented in the medical record.

Policy disclaimer to follow government LCD/NCD/Medicaid when applicable.
Testing of acute phase reactants and ESR is performed in laboratories meeting CLIA quality standards.

Note

No specific ordering-provider restrictions listed

No specific restrictions on which providers may order ESR/CRP are provided in these sections of the policy.

Definitions and Test Descriptions

CRP and ESR are non‑specific acute‑phase reactants used to detect and monitor inflammation. They are applied across a range of conditions including rheumatoid arthritis, polymyalgia rheumatica, giant cell arteritis, systemic lupus erythematosus, cardiovascular disease contexts, and select malignancies such as Hodgkin lymphoma. ESR is typically measured by Westergren methods and is influenced by plasma proteins and patient factors; CRP rises rapidly in acute inflammation and returns to baseline more quickly than ESR.

inv-49: CRP — Definition and notes

CRP definitionC‑reactive protein: an acute phase reactant produced by hepatocytes; rises rapidly in acute inflammation and infections and returns to normal quickly when inflammation resolves.

Clinical useUseful as a biomarker to monitor inflammatory response and to help distinguish infection from other causes of inflammation.

FormsIncludes conventional CRP, high‑sensitivity CRP (hsCRP), and cardiac CRP variants (FDA guidance referenced).

inv-50: ESR — Definition and notes

ESR definitionErythrocyte sedimentation rate (ESR): a laboratory method (commonly Westergren) measuring red cell sedimentation over one hour as an indirect marker of inflammation; results influenced by plasma proteins and patient factors.

Method variabilityWestergren is reference method; automated/non‑Westergren methods and anticoagulant differences (eg, EDTA vs citrate) can cause substantial variability.

KineticsESR rises and falls more slowly than CRP and can remain elevated for days after inflammation resolves.

inv-51: CRP — Additional context

CRP rapid kineticsCRP rises rapidly (can increase >1000‑fold in acute inflammation) and returns to normal quickly after resolution; useful for detecting acute changes and infection.

Assay formatsCRP assays available as EIA, rapid diagnostic tests, and latex agglutination; FDA has guidance for CRP/hsCRP/cCRP assay assessment.

Clinical implicationPreferred first‑line marker for suspected acute infection due to earlier elevation compared with ESR.

inv-52: ESR — Additional context

ESR influencesESR is affected by plasma proteins (eg, fibrinogen), red cell morphology, sample preparation, temperature, and anticoagulant used; interpretative caution is required.

Westergren referenceICSH/Westergren method is the calibration reference; automated methods may differ substantially and require laboratory‑specific interpretation.

Clinical noteBecause ESR changes more slowly, it may be less useful for rapid response monitoring compared with CRP.

inv-53: Composite disease activity indices (DAS28/SDAI/CDAI)

Composite indicesComposite disease activity indices (eg, DAS28, SDAI, CDAI) incorporate joint counts and may include CRP or ESR to assess rheumatoid arthritis activity and remission.

Guideline supportEULAR and ACR recommend using composite measures to monitor disease activity and guide treatment decisions.

Testing frequencyComposite monitoring typically performed every 1–3 months in active disease until control is achieved.

inv-54: LDT — Definition and regulatory note

LDT definitionLaboratory‑developed test (LDT): assays developed and validated by individual laboratories; regulated under CLIA as high‑complexity tests and not FDA‑cleared/approved for clinical use.

Regulatory noteLDTs are regulated by CMS under CLIA '88; FDA approval is not required for clinical use of LDTs per policy description.

Laboratory requirementTesting should be performed in CLIA‑compliant laboratories meeting applicable quality standards.

inv-55: hsCRP / cCRP — Assay variants and guidance

hsCRP / cCRP variantsHigh‑sensitivity CRP (hsCRP) and cardiac CRP (cCRP) are assay variants; FDA issued review criteria/guidance for assessment of these assays.

Clinical usehsCRP may be used for cardiovascular risk assessment while conventional CRP/hsCRP have different clinical applications; refer to FDA guidance and lab labeling.

Assay approvalFDA has approved multiple CRP assays including conventional, hsCRP, and cCRP formats.

OpenPayer

General Inflammation Testing (CRP and ESR)

Coverage Criteria for ESR and CRP

Indications and Condition-Specific Guidance

Recommended Monitoring Frequency

Procedure Codes and Numeric Thresholds

Provider Actions, Documentation, and Prior Authorization

Ordering and Laboratory Requirements

Not Covered / Low-Value Use

Definitions and Test Descriptions

Background and Evidence Summary

Referenced Studies and Professional Guidelines

Policy Revision History