CurrentUnitedHealthcarePolicy CS021PA.O

Collagen Crosslinks and Biochemical Markers of Bone Turnover (for Pennsylvania Only)

State-specific UnitedHealthcare medical policy for Pennsylvania regarding the use of serum or urine collagen crosslinks and biochemical bone turnover markers to assess fracture risk, predict bone loss, or monitor response to antiresorptive therapy.

Policy Summary

PayerUnitedHealthcare

PolicyCollagen Crosslinks and Biochemical Markers of Bone Turnover (for Pennsylvania Only)

Policy CodePolicy CS021PA.O

Change TypeSupporting information updated (Description of Services, Clinical Evidence, FDA, References)

Effective DateMarch 1, 2026

Next Review DateN/A

Key ActionWhen ordering or evaluating bone turnover marker testing, interpret results in the context of BMD and clinical fracture risk and follow state-specific case-by-case review procedures for requests that do not meet policy criteria.

SourceLink

POLICY UPDATE CHANGES

Updated Description of Services, Clinical Evidence, FDA, and References sections to reflect the most current information.

1CPT/Procedure code listed

Pennsylvania-onlyGeographic application

2026-03-01Effective date

Multiple society statementsGuideline sources summarized

Coverage Rationale and Criteria

Coverage Rationale

Serum or urine collagen crosslinks or biochemical markers are considered not medically necessary for the following clinical intents:

ANY of the following

Assess risk of fracture
Predict bone loss
Assess response to antiresorptive therapy

Professional Society Guidance and Usage Statements

Guidance and Usage Statements from Professional Societies

Summarized positions — these are recommendations from societies rather than payer coverage rules:

Society statements

ESCEO/IOF/IFCC (2025): Serum PINP and plasma β-CTX-I are reaffirmed as reference BTMs and considered useful for monitoring anti-osteoporosis therapy; BALP and TRACP5b recommended as reference markers for CKD-associated osteoporosis.
Endocrine Society: BTMs show promise as independent fracture predictors but further prospective cohort studies are needed; additional studies needed to relate BTM changes to fracture risk reduction to guide treatment targets.
ISCD (2023): Serial BMD testing in combination with clinical assessment, BTMs, and other factors can be used to determine need for treatment according to local guidelines.
ISCD/IOF (2023): Evidence that BTMs predict fracture risk independent of BMD is inconclusive; BTMs are not included as risk factors in FRAX.
NAMS (2021): BTMs cannot diagnose osteoporosis and have varying ability to predict fracture risk; routine use of BTMs in clinical practice is not recommended.

Monitoring recommendations from guidelines

When used for monitoring therapy, societies suggest timing and markers as follows:

Monitoring recommendations

For antiresorptive therapy, consider measuring a bone resorption marker (e.g., serum CTX or serum/urine NTx) at 3 to 6 months after treatment initiation.Timing for BTM measurement after treatment initiation: 3 to 6 months
For anabolic therapy, consider measuring a bone formation marker (e.g., serum PINP) at 3 to 6 months after treatment initiation.Timing for BTM measurement after treatment initiation: 3 to 6 months
Serial dual-energy X-ray absorptiometry (DXA) at the spine and hip every 1 to 3 years can assess response to treatment; BTMs are an alternative way to identify poor response or nonadherence.DXA monitoring interval: every 1 to 3 years

Referenced Procedure Codes

Referenced procedure codesCPT

82523

Collagen cross links, any method

No procedure or billing codes specified in this partmixed

No codes listed

Provider Guidance and Billing Impact

Documentation Required

Case-by-case review for exceptions

Requests that do not meet the policy criteria will be evaluated individually under Pennsylvania Exceptions (Pennsylvania Code, Title 55, Chapter 1101); providers should expect case-by-case review for exception requests.

Documentation Required

Use guidelines and clinical judgment when ordering BTMs

Clinicians should interpret bone turnover markers (BTMs) alongside bone mineral density (BMD), clinical fracture risk, and other factors; BTMs are not standalone diagnostic tests and their routine use is not universally recommended.

Clinical Background

Bone turnover markers (BTMs) are biochemical measures of bone formation and bone resorption that can be assayed in serum or urine. Examples of formation markers include P1NP, osteocalcin, and bone-specific alkaline phosphatase (BALP); examples of resorption markers include CTX (β-CTX-I), NTx, and pyridinoline. Commercial tests use methods such as high-performance liquid chromatography or immunoassay to quantify these analytes and are used in research and some clinical settings to characterize ongoing bone remodeling.[0,4]

BTMs have been investigated for several potential clinical uses: to assess the rate of bone remodeling, to help predict future fracture risk, and to monitor response to osteoporosis treatments (for example, assessing early suppression of resorption with antiresorptives or increases in formation with anabolic agents). Studies and guideline statements have evaluated specific thresholds and timing — for example, measuring a resorption marker such as serum CTX or NTx at 3 to 6 months after starting antiresorptive therapy and a formation marker such as P1NP at 3 to 6 months after initiating anabolic therapy — and some observational work has identified discrimination cutpoints (e.g., P1NP ≈ 30 μg/L and CTX ≈ 0.25 μg/L) correlated with treatment use or BMD changes in cohort studies.[4,12,29,28]

Despite promising associations in some studies and supportive commentary from specialty groups about potential roles for BTMs in monitoring and research, the policy’s position is that the clinical validity of collagen crosslinks and BTMs is unproven for routine use to assess fracture risk, diagnose osteoporosis, predict bone loss, or definitively monitor and guide therapy. UnitedHealthcare concludes that prospective, well‑designed trials and standardized assays are needed to demonstrate that use of BTMs improves patient outcomes before recommending routine clinical application.[5,3,28]

Numeric and Timing Thresholds

Key thresholds and monitoring intervals

P1NP discrimination threshold (from cited study)30 μg/L

CTX discrimination threshold (from cited study)0.25 μg/L

Least significant change for CTX (per BHOF statement)≈ 40% reduction for antiresorptive therapy

DXA monitoring intervalevery 1 to 3 years

Timing for BTM measurement after treatment initiation3 to 6 months

Policy Definitions

Definitions

BTMsBiochemical markers of bone turnover, including markers of bone formation (e.g., P1NP, osteocalcin, bone alkaline phosphatase) and bone resorption (e.g., CTX, NTx, pyridinoline).

PINPProcollagen type I N-terminal propeptide — a bone formation marker.

CTX (β-CTX-I)C-terminal cross-linking telopeptide of type I collagen — a bone resorption marker.

BALPBone-specific alkaline phosphatase — a formation marker, recommended for CKD-associated osteoporosis by ESCEO/IOF/IFCC.

TRACP5bTartrate-resistant acid phosphatase 5b — a resorption marker, recommended for CKD-associated osteoporosis by ESCEO/IOF/IFCC.

Policy Updates

2026-03-01clarifiedLatest

Updated Description of Services, Clinical Evidence, FDA, and References sections to reflect the most current information; archived previous policy version CS021PA.N.