ModifiedMolina HealthcarePolicy G2014

Vitamin B12 and Methylmalonic Acid Testing

Defines medical necessity and coverage limits for serum total vitamin B12 and methylmalonic acid (MMA) testing, and states when holotranscobalamin and homocysteine testing are not covered; applies to Molina Healthcare members under the policy G2014.

Policy Summary

PayerMolina Healthcare

PolicyVitamin B12 and Methylmalonic Acid Testing

Policy CodePolicy G2014

Change TypeFrequency and coverage clarificationsexclusions added

Effective DateNov 16, 2015

Next Review DateApr 1, 2025

Key ActionOrder total vitamin B12 testing only when listed clinical indications are documented and limit repeat testing to once every three months unless justified.

SourceLink

POLICY UPDATE CHANGES

Added a three month testing frequency for all vitamin B testing/screening and made it a main coverage criterion specifying total vitamin B12 testing meets coverage once every three months for listed situations.

New exclusion: For all other situations not described above, total vitamin B12 (serum cobalamin) testing does not meet coverage criteria (CC7).

Updated background, guidelines, and evidence-based scientific references.

3 monthsminimum repeat testing interval for vitamin B12 testing

Not coveredholotranscobalamin testing for screening/testing/confirmation

Not covered

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homocysteine testing for confirmation of B12 deficiency

>95%reported sensitivity of elevated serum MMA

82607,83090,83921,84999procedure codes listed

Coverage Criteria for Vitamin B12 and MMA Testing

inv cu-01: Total vitamin B12 (serum cobalamin) — medically necessary indications

Covered when ALL of the following are met as specified below for the indicated test groups

Total vitamin B12 testing (serum cobalamin): MEETS COVERAGE CRITERIA once every three months for any of: (a) individuals with listed signs and symptoms of vitamin B12 deficiency (cutaneous, gastrointestinal, hematologic, neuropsychiatric); (b) individuals undergoing treatment for vitamin B12 deficiency; (c) individuals with one or more listed risk factors for vitamin B12 deficiency (decreased ileal absorption including Crohn disease, ileal resection, tapeworm infection, or history of/anticipated bariatric procedures; decreased intrinsic factor such as atrophic gastritis, pernicious anemia, postgastrectomy syndrome; transcobalamin II deficiency; inadequate intake due to alcohol abuse, age >75, strict vegan diet or eating disorder; prolonged medication use including H2 blockers >12 months, metformin >4 months, or proton pump inhibitors >12 months)frequency: once every three months

See policy sections for full lists of signs, symptoms, and risk factors.

inv cu-02: Methylmalonic acid testing — medically necessary indications

Covered when ANY of the following are met

Methylmalonic acid (MMA) testing: MEETS COVERAGE CRITERIA for: (a) asymptomatic high-risk individuals with low-normal or normal serum vitamin B12 when deficiency is suspected to confirm vitamin B12 deficiency; (b) evaluation of inborn errors of metabolism.none

MMA is recommended as a confirmatory/metabolic marker when serum B12 is equivocal or for metabolic disorder evaluation.

inv cu-03: Medically necessary indications and follow-up

Covered when testing is ordered in accordance with guideline-recommended indications:

Indications: Order serum vitamin B12 (first-line) when the patient has suspected clinical manifestations (e.g., macrocytic anemia, leukopenia, pancytopenia, thrombocytopenia or -osis, glossitis, cognitive impairment, gait abnormalities, peripheral neuropathy, olfactory impairment, unexplained fatigue) or has risk factors (e.g., malabsorptive disorders, pernicious anemia/postgastrectomy syndrome, transcobalamin II deficiency, post-bariatric surgery, prolonged metformin or PPI use, strict vegan diet, age >75).

Supported by AAFP, AACE/ACE, ASMBS, BOMSS, NICE and consensus panel guidance.

When serum B12 is equivocal: If serum B12 is normal or low-normal but clinical suspicion persists (for example macrocytosis or neurologic signs), obtain plasma methylmalonic acid (MMA) or total homocysteine as a second-line test.

Recommended by AAFP, British Committee for Standards in Haematology, Vitamin B12 Consensus Panel.

Bariatric surgery context: Preoperative and routine post-operative screening for vitamin B12 is recommended for bariatric surgery patients; include MMA with or without homocysteine when evaluating metabolic deficiency. More frequent monitoring (e.g., every 3 months) is recommended in the first postoperative year and at least annually thereafter.

inv cu-04: Main coverage criterion and included situations

Covered when ALL of the following are met per the revised main criterion and supporting guidance:

Main criterion

Situations warranting testing: Includes: clinical signs/symptoms consistent with B12 deficiency (cutaneous, gastrointestinal, hematologic, neuropsychiatric manifestations), individuals undergoing treatment for B12 deficiency, presence of risk factors (restrictive diet, malabsorption, bariatric surgery, atrophic gastritis, pernicious anemia, transcobalamin II deficiency), prolonged medication exposures associated with low B12 (e.g., metformin), and recommended monitoring intervals for post-bariatric and chronic metformin users.
Derived from guideline and consensus recommendations.

inv cu-05: MMA / homocysteine testing criteria

Supporting coverage logic for metabolic markers:

Use of metabolic markers: Measurement of plasma methylmalonic acid (or total homocysteine if MMA unavailable) is useful to guide diagnosis of vitamin B12 deficiency, to monitor effectiveness of B12 treatment generally, and to monitor oral B12 treatment when absorption or dosing is in question.

Consensus panel and guideline statements support MMA (or Hcy if MMA unavailable) as the preferred metabolic marker.

Screening for vitamin B12 deficiency in healthy, asymptomatic individuals is explicitly excluded from coverage. The policy states that screening in healthy, asymptomatic individuals DOES NOT MEET COVERAGE CRITERIA, and testing in this population may be denied unless other covered indications are documented.

Holotranscobalamin (holoTC) testing is not a covered service for the screening, testing, or confirmation of vitamin B12 deficiency. The policy specifies that holotranscobalamin testing DOES NOT MEET COVERAGE CRITERIA, reflecting current guidance that holoTC is an emerging marker but not validated for routine clinical use.

Multiple guideline groups do not support routine screening of asymptomatic, average-risk individuals. The AAFP states it 'does not recommend screening persons at average risk' and recommends testing be limited to patients with risk factors or suspected clinical manifestations. The Doctors of BC similarly reports that 'routine B12 screening and testing in asymptomatic patients is not supported by evidence' and advises considering supplementation without testing in asymptomatic high-risk patients rather than routine population screening.

A new exclusion (CC7) was added: for all other situations not described in the policy's listed covered indications, total vitamin B12 (serum cobalamin) testing DOES NOT MEET COVERAGE CRITERIA. In addition, the policy operationalizes a minimum repeat testing interval by specifying that covered total vitamin B12 testing is allowed once every three months for the enumerated indications.

Measurement of total homocysteine for the purpose of confirming vitamin B12 deficiency is not covered. The policy states that homocysteine testing for confirmation of vitamin B12 deficiency DOES NOT MEET COVERAGE CRITERIA, with methylmalonic acid preferred as the metabolic confirmatory test when indicated.

All clinical situations not specified among the policy's covered indications for total vitamin B12 testing are not covered. The policy explicitly states that requests falling outside the described covered indications DO NOT MEET COVERAGE CRITERIA (see new CC7) and may be denied.

Routine B12 screening in asymptomatic patients without risk factors is not recommended. The AAFP recommends against average‑risk population screening and advises testing only for those with risk factors or clinical manifestations; The Doctors of BC likewise states routine screening of asymptomatic patients is unsupported and suggests targeted supplementation may be considered for some high-risk asymptomatic patients.

Repeat total vitamin B12 testing more frequently than once every three months is not supported unless justified by the listed clinical situations. The policy now operationalizes a 3‑month minimum interval for repeat testing and indicates repeat testing sooner than that may not meet coverage criteria unless clinical documentation supports an exception.

Specific Covered Indications

inv cu-34: Diagnosis or monitoring of vitamin B12 deficiency when signs/symptoms present; monitoring during treatment; high-risk individuals with equivocal B12 levels for confirmation using MMA; evaluation of inborn errors of metabolism.

Covered indications include diagnosis, monitoring, confirmation in equivocal cases, and evaluation of metabolic disorders:

Diagnosis or monitoring of vitamin B12 deficiency: Total B12 testing is covered for diagnosis or monitoring when signs or symptoms of deficiency are present (cutaneous, gastrointestinal, hematologic, neuropsychiatric) and for monitoring during treatment.

Per policy indications and listed symptom categories.

High-risk individuals with equivocal B12 levels: In asymptomatic high-risk individuals with low-normal or normal serum B12 but suspected deficiency, plasma MMA testing is covered to confirm deficiency.

Policy and consensus guidance recommend MMA as confirmatory test.

Evaluation of inborn errors of metabolism:

Testing Frequency and Monitoring Intervals

inv cu-38: Total vitamin B12 (serum cobalamin) — once every three months

TestTotal vitamin B12 (serum cobalamin)

Frequency limitOnce every three months

Covered situations (summary)Individuals with signs/symptoms of B12 deficiency, individuals undergoing treatment for B12 deficiency, or individuals with listed risk factors (e.g., malabsorption, pernicious anemia, post‑bariatric surgery)

inv cu-39: serum B12 (MMA optional/with indication) — Every 3 months in the first post-bariatric year, then at least annually

TestSerum vitamin B12 (with MMA optional/when indicated)

Frequency (post-bariatric)Every 3 months in the first postoperative year, then at least annually

Applicable Procedure Codes

Applicable CPT/HCPCS Procedure CodesCPT

82607	Cyanocobalamin (Vitamin B-12)
83090	Homocysteine
83921	Organic acid, single, quantitative
84999	Unlisted chemistry procedure

Provider Actions and Authorization Guidance

Prior Authorization

Alignment with Guideline-Specified Indications

Coverage for vitamin B12 testing is tied to specific clinical indications and guideline-recommended populations. Requests for testing that do not align with these indications, or that are for screening in healthy asymptomatic individuals, may be denied. Prior authorization may be required depending on the member's benefit plan and applicable state or federal rules. Documentation must support the clinical rationale for testing.

Total vitamin B12 (serum cobalamin) testing: covered once every 3 months when criteria met (signs/symptoms, risk factors, or during treatment).
Methylmalonic acid (MMA) testing: covered to confirm deficiency in high-risk asymptomatic individuals with low-normal B12 or when deficiency suspected; also covered for inborn errors of metabolism.
Homocysteine testing: NOT covered for confirmation of B12 deficiency.
Holotranscobalamin testing: NOT covered for screening, testing, or confirmation of B12 deficiency.
Screening in healthy, asymptomatic individuals: NOT covered.

Ordering and Documentation Requirements

Documentation Required

Ordering must include qualifying clinical documentation

Orders must be accompanied by documentation of qualifying clinical signs/symptoms, risk factors, treatment status, or metabolic indications per the covered criteria.

Ordering clinicians should ensure the medical record documents the reason the test meets one of the covered situations (signs/symptoms, risk factor, treatment monitoring, or inborn error).

Note

Order tests when signs/symptoms or risk factors are present

Order testing when clinical signs/symptoms or risk factors are documented; clinicians caring for bariatric patients, primary care, endocrinology, and relevant specialists may order testing per guideline recommendations.

ASMBS and AACE/ACE recommend routine pre- and post-bariatric screening and inclusion of MMA when indicated.
AAFP: perform laboratory evaluation including CBC and serum vitamin B12 for suspected deficiency.

Not Covered Tests and Situations

Holotranscobalamin testing for screening, testing, or confirmation; homocysteine testing for confirmation; and screening in healthy asymptomatic individuals are specifically listed as not covered. In sum, the policy states that these tests and screening contexts DO NOT MEET COVERAGE CRITERIA and represent common denial triggers when requested without a covered indication.

The one‑hour 13C‑propionate breath test is considered investigational/limited utility for routine clinical use. A small study (49 patients) found no significant correlation between the breath test results and low serum vitamin B12 levels, limiting its applicability as a clinical replacement for standard serum or metabolic testing.

Total vitamin B12 testing is not covered for indications not listed in the policy or when performed more frequently than the specified three‑month interval without supporting clinical justification. The policy's new CC7 and the revised frequency rule together limit coverage to the enumerated clinical situations and the defined testing interval.

Definitions and Key Terms

inv cu-29: Methylmalonic acid (MMA)

DefinitionMethylmalonic acid (MMA) is a metabolite that accumulates when vitamin B12 is unavailable and is considered an indicator of functional B12 deficiency.

Clinical useUsed as a second-line or confirmatory test when serum B12 is equivocal or to evaluate inborn errors of metabolism.

Analytic noteElevated serum MMA has reported sensitivity >95% for overt cobalamin deficiency (specificity variable).

inv cu-30: Holotranscobalamin (holoTC)

DefinitionHolotranscobalamin (holoTC) is the metabolically active fraction of vitamin B12 and an emerging marker of impaired B12 status.

Clinical availabilityNot yet clinically validated or widely available for routine use per current evidence summaries.

Background and Rationale

Vitamin B12 (cobalamin) is essential for hematologic and neurologic function; deficiency can cause reversible hematologic abnormalities and neuropsychiatric disorders. Methylmalonic acid (MMA) accumulates when B12 is unavailable and serves as a functional indicator of deficiency, while holotranscobalamin is the metabolically active fraction and an emerging but not yet widely validated marker. Consensus guidance supports using metabolic markers like MMA (or homocysteine if MMA is unavailable) to help confirm diagnosis and monitor treatment when clinical suspicion or equivocal serum B12 levels exist.

Policy Summary

PayerMolina Healthcare

PolicyVitamin B12 and Methylmalonic Acid Testing

Policy CodePolicy G2014

Change TypeFrequency and coverage clarificationsexclusions added

Effective DateNov 16, 2015

Next Review DateApr 1, 2025

Key ActionOrder total vitamin B12 testing only when listed clinical indications are documented and limit repeat testing to once every three months unless justified.

SourceLink

On This Page

Supported by ASMBS, AACE/ACE, BOMSS.

Monitoring specific groups: Consider periodic assessment (e.g., annually) of B12 in chronic metformin users and in patients with diabetes with peripheral neuropathy or unexplained anemia to detect deficiency before clinical manifestation.

Supported by Vitamin B12 Consensus Panel and ADA/AACE guidance.

Methylmalonic acid testing meets coverage criteria for evaluation of inborn errors of metabolism.

Explicitly listed in policy indications.

inv cu-35: Suspected vitamin B12 deficiency with clinical manifestations (hematologic, neurologic, cutaneous, GI) or risk factors (malabsorption, bariatric surgery, long-term metformin/PPI use, strict vegan diet, age >75).

Covered when clinical manifestations or risk factors are present:

Suspected vitamin B12 deficiency with clinical manifestations or risk factors: Order serum B12 (first-line) for patients with hematologic (macrocytic/megaloblastic anemia, leukopenia, pancytopenia, thrombocytopenia or thrombocytosis), neurologic/neuropsychiatric (areflexia, cognitive impairment, gait abnormalities, peripheral neuropathy, loss of proprioception/vibratory sense, olfactory impairment), cutaneous (hyperpigmentation, jaundice, vitiligo), or gastrointestinal (glossitis) manifestations, or for patients with risk factors including decreased ileal absorption (Crohn disease, ileal resection, tapeworm), decreased intrinsic factor (atrophic gastritis, pernicious anemia, postgastrectomy syndrome), genetic transcobalamin II deficiency, inadequate intake (alcohol abuse, strict vegan diet, age >75), or prolonged medication use (H2 blockers >12 months, metformin >4 months, PPIs >12 months).

If serum B12 is equivocal, obtain MMA or homocysteine as second-line testing.

inv cu-36: Preoperative and postoperative screening in patients undergoing bariatric/metabolic surgery.

Covered in the perioperative and postoperative bariatric surgery context when testing is guideline-directed:

Preoperative and postoperative screening for bariatric/metabolic surgery patients: Routine preoperative screening for vitamin B12 is recommended for all patients undergoing metabolic/bariatric surgery; postoperatively, include more frequent monitoring (e.g., every 3 months in the first year) and at least annual assessment thereafter. Consider including MMA (with or without homocysteine) to identify metabolic B12 deficiency in symptomatic and asymptomatic patients and in those with prior B12 deficiency or neuropathy.first year: every 3 months; thereafter at least annually

Supported by AACE/ACE, ASMBS, BOMSS guidelines.

inv cu-37: Suspected vitamin B12 deficiency with supportive symptoms or risk factors (e.g., anemia/macrocytosis, cognitive impairment, neuropathy, restrictive diet, malabsorption, bariatric surgery, chronic metformin use).

Covered when supportive symptoms or risk factors are present and metabolic markers are indicated:

Suspected deficiency with supportive symptoms or risk factors: In patients with anemia or macrocytosis, cognitive impairment, neuropathy, restrictive diet, malabsorption, history of bariatric surgery, or chronic metformin use, serum B12 testing is indicated as first-line; plasma MMA or total homocysteine should be used adjunctively when available to aid diagnosis or monitoring.

Consensus and NICE guidance recommend availability of metabolic markers for suspected cases.

ContextRecommended for baseline and postoperative monitoring after bariatric/metabolic surgery; consider MMA adjunctively to identify metabolic deficiency

inv cu-40: serum B12 — Consider annually

TestSerum vitamin B12 (considered)

Suggested frequencyConsider annually

PopulationChronic metformin users and patients with diabetes and peripheral neuropathy or unexplained anemia (per guideline guidance)

inv cu-41: Total vitamin B12 (serum cobalamin) — once every 3 months

TestTotal vitamin B12 (serum cobalamin)

Frequency limitOnce every three months

NotesApplies when covered indications are met (signs/symptoms, treatment monitoring, or listed risk factors). Repeats more frequently than 3 months without justification are not supported.

inv cu-42: Vitamin B12 status monitoring for chronic metformin users — once per year

Monitoring indicationVitamin B12 status monitoring for chronic metformin users

Recommended frequencyOnce per year

RationaleChronic metformin use is associated with lower B12 concentrations and increased neuropathy risk; annual assessment can detect deficiency prior to symptoms.

Denial Risk

Testing Without Clinical Indication or Outside Guidelines

Testing without clinical indication or outside guideline-recommended contexts lacks demonstrated clinical utility and is at high risk for denial. Requests for tests that exceed the allowed frequency (more often than every three months for covered serum B12 testing) or that are submitted for screening of asymptomatic, average-risk individuals are likely to be denied under coverage criteria.

Denial triggers include: screening of healthy asymptomatic individuals; holotranscobalamin testing for screening/testing/confirmation; testing more frequently than every 3 months without documented clinical justification.
Excessive frequency or non-listed indications may be denied under CC7.

Documentation Required

Required Clinical Documentation

Document clinical manifestations, risk factors, treatment status, or other supporting findings in the medical record. Clinical documentation must justify the medical necessity of the requested test and demonstrate alignment with covered indications.

Record one or more qualifying signs or symptoms (e.g., macrocytic anemia, peripheral neuropathy, cognitive impairment, glossitis, gait abnormalities).
Record relevant risk factors (e.g., prior bariatric surgery, pernicious anemia, prolonged metformin or PPI use, advanced age >75, vegan diet, ileal resection, Crohn's disease).
If serum B12 is normal or low-normal but clinical suspicion remains, document need for MMA or total homocysteine as the next-step diagnostic test.
For patients on chronic metformin or with prior bariatric surgery, document history and any prior supplementation or monitoring that supports more frequent testing as per guidelines.
Include recent CBC results or other lab abnormalities (e.g., macrocytosis) when relevant.

Documentation Required

Order tests when symptom + risk factor or clinical judgment indicate

Order testing when a patient presents with both a common symptom and a common risk factor for B12 deficiency, or when clinical judgment indicates testing; consider reflex testing to MMA or homocysteine when total B12 is indeterminate.

NICE: test when patients display both a common symptom and a common risk factor; use clinical judgment if only symptoms are present.
Consensus: make plasma MMA (or total homocysteine if MMA unavailable) available for suspected cases and consider reflex testing strategies.

RoleMay detect depletion earlier than total B12 but specificity and widespread clinical validation remain limited.

inv cu-31: Metabolic marker

DefinitionMetabolic marker: plasma methylmalonic acid (MMA) or total homocysteine used to detect functional vitamin B12 deficiency and to monitor treatment response.

Preferred markerPlasma MMA is preferred; total homocysteine may be used if MMA unavailable.

Use casesHelpful when serum B12 is indeterminate and for monitoring oral B12 treatment effectiveness.

inv cu-32: MMA

TermMethylmalonic acid (MMA)

Clinical significanceA metabolic marker elevated in B12 deficiency used to guide diagnosis and monitor treatment effectiveness.

Testing contextRecommended as adjunctive/confirmatory testing when serum B12 is equivocal or to monitor therapy if available.

inv cu-33: Total vitamin B12

TermTotal vitamin B12 (serum cobalamin)

PurposeMeasurement of circulating cobalamin used as an initial (first-line) test for suspected deficiency.

Follow-upIf serum B12 is normal or low-normal but clinical suspicion remains, obtain plasma MMA or total homocysteine as a second-line test.