Modifiedmedical mutual - ohioPolicy AHS - G2164

Parathyroid Hormone, Phosphorus, Calcium, and Magnesium Testing

Medical Mutual - Ohio coverage policy for laboratory testing of parathyroid hormone (PTH), calcium, phosphorus, and magnesium, describing when tests are covered, limitations, and analytic considerations for providers and labs.

Policy Summary

Payermedical mutual - ohio

PolicyParathyroid Hormone, Phosphorus, Calcium, and Magnesium Testing

Policy CodePolicy AHS - G2164

Change TypeConsolidated criteria and added surveillance frequencies

Effective DateMar 1, 2019

Next Review Date

Key ActionDocument the clinical indication and applicable testing frequency when ordering PTH, and follow the specified surveillance intervals for CKD and pseudohypoparathyroidism.

SourceLink

POLICY UPDATE CHANGES

Wrapped CC1 and CC2 into a single criterion to describe all appropriate testing indications for PTH and consolidated multiple indications and frequency rules into one criterion.

Added Note 1 defining signs of hypoparathyroidism (hypocalcemia, elevated serum phosphorus, low calcitriol, hypercalciuria, abnormal magnesium).

Specified surveillance testing frequencies for PTH in chronic kidney disease: Grade 3 = annually; Grade 4 or 5 = every three months.

Specified age-based testing frequency for pseudohypoparathyroidism or related disorders: <18 years = every 3 months; >=18 years = every year.

Multiplecovered indications for serum intact PTH

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Coverage Criteria for PTH, Calcium, Phosphorus, and Magnesium Testing

inv-01: Covered: Serum intact PTH

Serum intact PTH testing MEETS COVERAGE CRITERIA when ANY of the following are present:

Covered indications for serum intact PTH: a) For individuals with abnormal calcium levels.

Covered indications for serum intact PTH: b) One-time testing for the diagnosis of hypoparathyroidism for individuals with signs of hypoparathyroidism (see Note 1).

Covered indications for serum intact PTH: c) For individuals with osteoporosis or low bone mass.

Covered indications for serum intact PTH: d) For individuals who have undergone parathyroidectomy.

Covered indications for serum intact PTH: e) One test every year for individuals diagnosed with hyperparathyroidism who have not undergone parathyroidectomy.

Covered indications for serum intact PTH: f) For individuals with chronic kidney disease (CKD): i) Grade 3 CKD: one test every twelve months; ii) Grade 4 or Grade 5 CKD: one test every three months.

Covered indications for serum intact PTH: g) One-time testing for individuals with multiple endocrine neoplasia type 2A (MEN2A) or familial medullary thyroid carcinoma.

Covered indications for serum intact PTH: h) For individuals with pseudohypoparathyroidism or related disorders: i) <18 years: one test every three months; ii) ≥18 years: one test every year.

inv-02: Not covered / Screening / Experimental fragments

The following testing situations DO NOT MEET COVERAGE CRITERIA:

Not covered — screening and routine tests: Serum intact PTH testing to screen for asymptomatic hyperparathyroidism.

Not covered — wellness/general exam without abnormal findings: For individuals presenting for a wellness visit or general exam without abnormal findings: a) serum, blood, or fecal magnesium testing; b) serum phosphorus/phosphate testing; c) urine phosphorus/phosphate testing; d) serum total calcium, serum ionized calcium, or urine calcium testing; e) serum parathyroid hormone testing in the wellness/general exam context.

Not covered — experimental fragments: Testing serum for truncated parathyroid hormone metabolites (e.g., amino-terminal and carboxy-terminal fragments) DOES NOT MEET COVERAGE CRITERIA due to lack of published evidence of clinical benefit.

inv-03: Guideline-aligned testing

Covered when aligned with guideline-based clinical indications and monitoring intervals

Evaluation of suspected primary hyperparathyroidism: Measure serum total calcium AND PTH AND creatinine AND 25-hydroxyvitamin D as part of the biochemical evaluation (AAES Recommendation 1-1).

24-hour urine in differential diagnosis: Consider 24-hour urine calcium and creatinine to differentiate familial hypocalciuric hypercalcemia (FHH) when indicated; urinary calcium <10 mg/24h and Ca/creatinine clearance ratio <0.01 suggest FHH (AAES Recommendation 1-2).

Post-parathyroidectomy assessment: Longitudinal testing should include calcium, PTH, and 25-hydroxyvitamin D with assessment for cure at 6 months post-op (AAES Rec 14-7); failure to normalize PTH at 6 months suggests persistent/recurrent disease.

inv-04: Pseudohypoparathyroidism monitoring

Covered when monitoring or diagnosing pseudohypoparathyroidism and related disorders

Initial and routine monitoring in pseudohypoparathyroidism: Measure serum PTH, calcium, phosphorus, and 25-hydroxyvitamin D at diagnosis or before initiation of treatment; monitor PTH, calcium and phosphorus every six months in children and at least yearly in adults (more frequent when symptomatic, during growth, pregnancy, or illness).

inv-05: Oncology indications

Covered when indicated for cancer diagnosis, surveillance, or TLS risk management per NCCN

Oncology-related indications: Measurement of calcium (and when indicated PTH), phosphorus, and magnesium is included in specified NCCN panels (e.g., MEN syndromes, TLS monitoring in ALL and CLL/SLL, multiple myeloma, bone tumor workup); TLS monitoring requires serial measurements timed to therapy dosing and tumor burden per NCCN tables.

inv-06: Covered when guideline-based clinical indications and monitoring intervals are met

Coverage consistent with guideline-recommended testing when aligned with clinical indications and monitoring intervals:

CKD monitoring: For patients with CKD, measure serum calcium, phosphate, PTH, and alkaline phosphatase beginning in CKD G3a and follow KDIGO/NKF tables for reasonable monitoring intervals (e.g., G3a-G3b: calcium/phosphate every 6–12 months; G4: every 3–6 months; G5: every 1–3 months; PTH intervals per guideline).

Post-kidney transplant monitoring: Measure calcium, phosphorus, PTH and total CO2 based on time after transplant (e.g., frequent early measurements per NKF KDOQI); monitor and manage persistent abnormalities accordingly.

Suspected primary hyperparathyroidism in primary care: Initial diagnostic testing should include albumin-adjusted serum calcium and PTH; repeat elevated albumin-adjusted calcium on separate occasions before diagnosis and perform concurrent sampling of PTH and calcium (NICE).

Chronic hypoparathyroidism monitoring:

inv-07: Covered clinical contexts (guideline-based)

Testing and monitoring are supported when tied to the following clinical contexts per cited specialty guidelines:

Guideline-supported clinical contexts: Includes: baseline serum calcium prior to bisphosphonate therapy and periodic monitoring during IV bisphosphonate treatment (ASCO/CCO); laboratory evaluation for secondary osteoporosis including PTH, phosphate, 25-OH vitamin D, CMP and 24-hour urine calcium when indicated (AACE/ACE); avoid routine serum magnesium monitoring in pregnancy unless indicated (SOGC); standard heart failure evaluation includes serum electrolytes including calcium and magnesium (AHA/ACC/HSFA); perioperative and bariatric surgery evaluations may include PTH, calcium, phosphorus, 25-OH vitamin D, and 24-hour urine calcium per specialty guidance.

inv-08: Covered: Indications and frequency for Serum intact PTH

Serum intact parathyroid (PTH) testing MEETS COVERAGE CRITERIA in any of the following situations:

PTH coverage indications consolidated: a) For individuals with abnormal calcium levels.

PTH coverage indications consolidated: b) One-time testing for the diagnosis of hypoparathyroidism for individuals with signs of hypoparathyroidism (see Note 1: hypocalcemia; elevated serum phosphorus; low calcitriol; hypercalciuria; abnormal magnesium).

PTH coverage indications consolidated: c) For individuals with osteoporosis or low bone mass.

PTH coverage indications consolidated: d) For individuals who have undergone parathyroidectomy.

Testing of serum for truncated parathyroid hormone metabolites (for example, amino-terminal and carboxy‑terminal fragments) does not meet coverage criteria. The policy excludes these fragment assays due to lack of published scientific literature demonstrating clinical utility for diagnosis or management.

The policy discourages over‑testing of electrolytes in the emergency setting. Use of validated clinical decision tools to target testing of serum calcium, magnesium, and phosphate is supported by the evidence cited, since such tools can limit testing to patients with clinical risk factors and have a high negative predictive value for clinically important abnormalities.

The National Institute for Health and Care Excellence (NICE) guidance referenced in the policy does not recommend routine measurement of calcium, phosphate, PTH, and vitamin D in people with estimated GFR ≥ 30 ml/min/1.73 m2 (GFR categories G1–G3). NICE does recommend these tests for patients in GFR categories G4 or G5 and advises determining testing frequency by measured values and clinical circumstances.

Routine metabolic testing (including serum calcium) for infants with lower‑risk brief resolved unexplained events (BRUE) and routine metabolic testing for patients with chronic constipation in the ambulatory setting are discouraged. The AAP recommends against routine metabolic panels (including calcium) for lower‑risk BRUE, and the AGA advises that metabolic testing for chronic constipation without other clinical features is generally not recommended.

The provided excerpt does not list additional explicit exclusions beyond those specified. Tests ordered outside the policy’s listed indications or outside the specified surveillance frequencies are implied to not meet coverage criteria and may be denied.

Screening for asymptomatic hyperparathyroidism and routine measurement of magnesium, phosphorus, calcium, and PTH performed as part of wellness or general exam visits without abnormal findings are identified as not meeting coverage. These routine screening tests during wellness encounters are considered unsupported by the policy and may be denied.

The policy notes that routine, indiscriminate electrolyte testing in low‑risk patients who lack clinical risk factors may be unnecessary. Evidence cited supports using targeted testing strategies because broad, unselected electrolyte testing yields little additional diagnostic benefit in low‑risk populations.

Reiterating the NICE position cited in this policy: routine measurement of calcium, phosphate, PTH, and vitamin D is not recommended for people with GFR ≥ 30 ml/min/1.73 m2 (CKD stages G1–G3). Testing should be reserved for patients with clinical indications or those in more advanced CKD (G4–G5).

Society guidance referenced by the policy advises against routine serum magnesium monitoring in pregnancy (SOGC 2014) and advises that routine metabolic testing including calcium for lower‑risk infants with BRUE is not recommended (AAP). These routine practices should be avoided unless clinical indications exist.

Testing that does not conform to the consolidated, listed indications for serum intact PTH or that exceeds the policy’s specified surveillance frequencies is considered to not meet coverage criteria. Providers should document the clinical indication and adherence to the policy frequency rules to support coverage.

Applicable Procedure Codes and Frequency Highlights

Applicable CPT/HCPCS Procedure Codes (listed later in document)mixed

No codes listed

Referenced laboratory tests (no codes listed)mixed

No explicit CPT/HCPCS codes in these chunks

Document references laboratory tests generically (calcium, PTH, phosphate, magnesium) and panels (TLS panel) but does not list billing codes.

Applicable CPT CodesCPT

82310	Calcium; total.
82330	Calcium; ionized.
82340	Calcium; urine quantitative, timed specimen.
83735	Magnesium.
83970	Parathormone (parathyroid hormone).
84100	Phosphorus inorganic (phosphate).
84105	Phosphorus inorganic (phosphate); urine

PTH testing frequency for CKD

CKD Grade 3 monitoring intervalOne intact PTH test every 12 months

CKD Grade 4 monitoring intervalOne intact PTH test every 3 months

CKD Grade 5 monitoring intervalOne intact PTH test every 3 months

PTH testing frequency for hyperparathyroidism without parathyroidectomy

Hyperparathyroidism without parathyroidectomyOne intact PTH test every 12 months (one test every year)

ContextApplies to individuals diagnosed with hyperparathyroidism who have not undergone parathyroidectomy

Documentation, Prior Authorization, and Actionable Provider Guidance

Documentation Required

Coverage requires indication and frequency

Coverage of serum intact parathyroid hormone (PTH) testing is limited to the specific clinical indications and frequencies listed in the policy. Providers must ensure testing is ordered only for covered indications (e.g., abnormal serum calcium, diagnosis of hypoparathyroidism with signs, osteoporosis/low bone mass, post-parathyroidectomy monitoring, annual monitoring for untreated hyperparathyroidism, CKD-stage–based monitoring, one-time testing for MEN2A/familial medullary thyroid carcinoma, and age-based monitoring for pseudohypoparathyroidism and related disorders). Routine screening for asymptomatic hyperparathyroidism and PTH testing during general wellness visits without abnormal findings are not covered.

Ensure frequency rules are followed (e.g., annual PTH for hyperparathyroidism without parathyroidectomy; CKD: G3 = every 12 months, G4/G5 = every 3 months; pseudohypoparathyroidism: <18 y = every 3 months, ≥18 y = annually).
One-time diagnostic PTH testing allowed for hypoparathyroidism when signs are present (see Note 1).
Do not order PTH to screen asymptomatic individuals for hyperparathyroidism.

Prior Authorization

Background and Rationale

Parathyroid hormone (PTH), calcitriol, and fibroblast growth factor 23 (FGF23) are central regulators of calcium and phosphate homeostasis. PTH increases ionized calcium through bone resorption and renal effects, and interacts with vitamin D metabolism and renal phosphate handling. These physiologic relationships provide the rationale for targeted testing of serum calcium, phosphate, PTH, and magnesium in appropriate clinical contexts described in the policy.

Definitions and Key Terms

iPTH / intact parathyroid hormone

DefinitionIntact circulating parathyroid hormone measurement; referenced throughout as serum intact PTH (iPTH)

Assay considerationsSecond- and third-generation intact PTH assays measure biologically active PTH; specimens and assay generation affect results

Sample stability notePlasma is more stable than serum for PTH at room temperature; follow assay-specific handling guidance

PO43- / phosphorus

TermPhosphorus in its oxidized phosphate polyatomic ionic form (PO43-)

MeasurementCommonly measured as serum inorganic phosphate

Policy Revision History

2019-03-01effective_date

Policy initial presentation/effective date for AHS - G2164 (Parathyroid Hormone, Phosphorus, Calcium, and Magnesium Testing).

2025-03-05material_revisionLatest

Reviewed and updated background, guidelines, recommendations, and evidence; consolidated prior separate PTH criteria (CC1 and CC2) into a single unified PTH coverage criterion and added operational frequency rules for CKD and pseudohypoparathyroidism and a new Note 1 defining signs of hypoparathyroidism.

Policy Summary

Payermedical mutual - ohio

PolicyParathyroid Hormone, Phosphorus, Calcium, and Magnesium Testing

Policy CodePolicy AHS - G2164

Change TypeConsolidated criteria and added surveillance frequencies

Effective DateMar 1, 2019

Next Review Date

Key ActionDocument the clinical indication and applicable testing frequency when ordering PTH, and follow the specified surveillance intervals for CKD and pseudohypoparathyroidism.

SourceLink

On This Page

Hypercalcemia thresholds and related guidance

Mild hypercalcemia threshold commonly citedSerum calcium >10.5 mg/dL — prompts consideration of PTH measurement

Moderate-range examplePatients with calcium 11.1–11.5 mg/dL were most likely to have primary hyperparathyroidism (study data)

Marked hypercalcemia>12 mg/dL — patients with these levels were most likely to have PTH measured and warrant evaluation

Corrected calcium referenceNormal reference noted as 8.5–10.2 mg/dL in NCCN context; use albumin-adjusted (corrected) calcium when evaluating hypercalcemia

Billing Rule

Applicable procedure codes

Use the applicable CPT/HCPCS codes listed in the policy when submitting claims for calcium, magnesium, phosphorus, and PTH testing. Providers must include clinical documentation supporting the medical necessity for the billed tests.

Covered procedure codes include (not all-inclusive): 82310, 82330, 82340, 83735, 83970, 84100, 84105.
Submit appropriate documentation (see documentation block) with claims to support medical necessity.

Denial Risk

Denial triggers

Testing that does not meet the specified indications or frequency may be denied. Common denial triggers include routine screening PTH for asymptomatic hyperparathyroidism and electrolyte/hormone tests ordered during wellness visits without abnormal findings.

Ordering PTH to screen asymptomatic individuals for hyperparathyroidism is a denial trigger.
Ordering serum magnesium, phosphorus, calcium, or PTH as part of a general wellness exam without abnormal findings may be denied.

Note

Risk from missing PTH testing

Failure to measure PTH when clinically indicated (for example, in the evaluation of hypercalcemia) risks under-diagnosis and under-treatment of primary hyperparathyroidism (PHPT). Documented clinical evaluation should include concurrent calcium measurement and appropriate follow-up testing per guidelines.

Ensure PTH is obtained when evaluating abnormal serum calcium to avoid missed PHPT diagnoses.
Document rationale for not obtaining PTH if it was clinically contraindicated or deferred.

Documentation Required

CKD testing frequency adherence

For patients with chronic kidney disease (CKD), adhere to guideline-based monitoring intervals when ordering serum calcium, phosphorus, and PTH to meet coverage expectations and to guide management.

KDIGO/NKF guidance: CKD G3a-G3b — calcium and phosphate every 6–12 months; PTH based on baseline and progression.
CKD G4 — calcium and phosphate every 3–6 months; PTH every 6–12 months.
CKD G5 — calcium and phosphate every 1–3 months; PTH every 3–6 months.
Follow transplant monitoring schedules per NKF KDOQI (e.g., more frequent checks in first year post-transplant).

Note

Conflict with government policy

If a conflict exists between this policy and any applicable government policy (e.g., LCDs/NCDs for Medicare, or state Medicaid rules), the applicable government policy takes precedence and will be applied to determinations for affected members.

Consult CMS and state Medicaid guidance when treating Medicare or Medicaid beneficiaries; government determinations override this policy where conflicts occur.
Provide documentation demonstrating which policy was applied in adjudication when requested.

Denial Risk

Denial risk for non-indicated testing

Testing that falls outside the consolidated indications and frequency rules may be denied as not meeting coverage criteria. Providers should anticipate requests for additional clinical documentation when tests are ordered outside of the listed covered situations.

Be prepared to supply clinical records demonstrating the covered indication and the need for the requested frequency of testing.
Non-indicated repeat testing or routine monitoring outside guideline intervals is at higher risk for denial.

Documentation Required

Required clinical documentation

Document the clinical indication and supporting data with every PTH and related electrolyte test order. Adequate documentation reduces denial risk and supports medical necessity determinations.

For suspected primary hyperparathyroidism: document albumin-adjusted serum calcium and a concurrent PTH measurement.
For CKD monitoring: document CKD stage, prior levels, and rationale for chosen monitoring frequency.
For perioperative thyroidectomy or parathyroidectomy: document pre-/post-operative calcium and/or intact PTH values and any treatments provided.
For hypoparathyroidism evaluation: document signs/symptoms (e.g., hypocalcemia, elevated phosphorus, low calcitriol, hypercalciuria, abnormal magnesium).
For pseudohypoparathyroidism and related disorders: document genetic diagnosis or clinical criteria and age to justify monitoring frequency.

Note

Testing stewardship

Use clinical decision-support tools and targeted ordering strategies to reduce unnecessary electrolyte and hormone testing. Stewardship helps avoid low-value testing and potential denials.

Apply decision rules that trigger PTH testing only when preceding calcium or clinical findings indicate need.
Avoid reflexive ordering of broad electrolyte panels during wellness visits unless clinically justified.

Note

Therapeutic sequence impacts monitoring

When monitoring disorders that affect phosphate handling (e.g., CKD with hyperphosphatemia), consider guideline-recommended therapeutic sequencing (e.g., progression of phosphate binder choices) because treatment choices impact monitoring needs and interpretation of labs.

Document changes in phosphate binder therapy and rationale; monitor phosphate, calcium, and PTH per guideline intervals after therapeutic changes.
If calcium-based binders are used and serum calcium rises, consider reducing dose or switching to non-calcium binders per guideline recommendations and document the decision.

Note

Recommended evaluation sequence

Follow a stepwise evaluation when assessing hypercalcemia, suspected primary hyperparathyroidism, or preoperative assessment for thyroid/parathyroid surgery: initial calcium measurement (albumin-adjusted or ionized as appropriate) followed by PTH measurement and additional tests (e.g., 25-OH vitamin D, creatinine, 24-hour urine calcium) as indicated.

Initial workup of suspected PHPT: albumin-adjusted serum calcium plus PTH, creatinine, and 25-hydroxyvitamin D.
Consider 24-hour urine calcium when differentiating familial hypocalciuric hypercalcemia from PHPT.
For preoperative thyroidectomy patients, assess calcium and consider PTH per ATA recommendations.

Step Therapy

Step therapy

No formal step-therapy requirements are specified in this policy excerpt for laboratory testing. Coverage depends on meeting the clinical indications and frequency criteria rather than progression through step-therapy tiers.

If a payer implements step-therapy-like prior authorization for laboratory testing, follow that program and document why earlier steps are not appropriate.

Documentation Required

PROVIDER ACTIONS

Providers should ensure required documentation accompanies orders and claims to demonstrate the clinical indication and adherence to frequency rules. When tests are ordered for covered indications, retain records showing the supporting laboratory values, clinical signs/symptoms, CKD stage, perioperative status, genetic diagnoses, or other relevant data to substantiate medical necessity.

Include concurrent serum calcium (albumin-adjusted or ionized) when ordering PTH for hypercalcemia evaluation.
Document CKD stage and prior results when ordering PTH at CKD-specific intervals.
For postoperative monitoring, include operative notes and immediate post-op labs when applicable.
Retain documentation of signs of hypoparathyroidism or genetic confirmation for pseudohypoparathyroidism cases.