VUS Reclassification: What Labs Owe Ordering Clinicians
Short answer: A laboratory that reports a variant of uncertain significance (VUS) should have a written policy for re-reviewing it and for telling the ordering clinician when its classification changes. ACMG calls recontact a shared responsibility, but places the duty to notify the ordering physician of a reclassification on the laboratory.
For molecular labs and medical directors, variant reclassification is no longer an edge case. Every VUS in a released report is a future obligation, and the evidence suggests most eventually resolve in the benign direction. This article reviews what the published data show about how often and in which direction reclassification happens, what ACMG expects from laboratories, and how to turn those expectations into an operational workflow. It is decision support for laboratory and clinical leadership, not legal advice.
Why VUS reclassification is a lab operations issue
A VUS is, by definition, a placeholder. The classification reflects the evidence available on the report date under the ACMG/AMP framework, and evidence accumulates after the patient leaves. Population frequency databases grow, functional assays are published, and other laboratories submit observations to ClinVar. The laboratory that issued the original report is the only party that holds the original evidence file, which is why the duty to revisit it falls most naturally on the lab.
The operational question is not whether reclassification will happen, but how many reports in your archive will be affected, how you will find them, and who will tell the clinician. Labs that cannot answer those three questions are carrying unmeasured risk. Our guide on hereditary cancer retesting after negative panels covers a related decision point on the clinical side.
What the data show: how often VUS get reclassified
The largest public analysis of reclassification behaviour is the ClinVar study by Harrison and Rehm, published in Genome Medicine in 2019. Covering submissions from 1 January 2016 to 1 July 2019, the authors examined 571,850 classifications across the five ACMG/AMP terms. Overall, 0.79 percent (4,501) were reclassified during that window. For VUS specifically, 0.95 percent (2,584 of 272,581) were reclassified.
That number looks small, and it needs context. It reflects a roughly three-and-a-half-year observation window across the whole public database, including many classifications that were submitted once and never revisited. It should not be read as a per-patient probability over a longer horizon. The same paper's authors caution that their estimates are preliminary and that they could not confirm every post-2016 classification used the 2015 ACMG/AMP guidelines.
The direction matters as much as the rate. Of the 2,584 VUS that were reclassified, 74.6 percent (1,927) moved to likely benign or benign, while 25.4 percent (657) moved to likely pathogenic or pathogenic. The practical implication for a lab is that most reclassification notices will be reassurance rather than alarm, but the minority that move toward pathogenic are the ones with the greatest clinical consequence, so your workflow must be able to prioritise them.
Likely pathogenic is not immune
Recontact policies sometimes focus only on VUS. The ClinVar data suggest that is too narrow. Likely pathogenic (LP) had the highest reclassification rate of any category at 2.16 percent (796 classifications). Of those, 78.52 percent (625) were upgraded to pathogenic, 20.73 percent (165) moved to VUS, and 0.75 percent (6) moved to likely benign or benign.
Harrison and Rehm calculated that, counting only definitive reclassifications, 99.7 percent (625 of 627) of reclassified LP variants ended up pathogenic rather than benign. Including those that fell back to VUS, they described an 83.8 percent figure as a worst-case scenario. For a laboratory, the lesson is that a downgrade from LP to VUS does occur, roughly one in five LP reclassifications in this dataset, and a recontact policy that ignores downgrades leaves clinicians acting on stale information.
A focused re-review: the BRCA1/2 single-centre experience
Population-scale data tell you the shape of the problem. A single-centre series shows what a systematic re-review looks like in practice. Innella and colleagues, writing in the Journal of Medical Genetics in 2024, re-examined 166 BRCA1 and BRCA2 VUS from 2011 to 2022 using ACMG/AMP rules specified for those genes by ENIGMA. They were able to classify 135 of 166 (81.3 percent). Of those, 128 (94.8 percent) became benign or likely benign and 7 (5.2 percent) became pathogenic or likely pathogenic.
The timing finding is the one operations teams should note. The average time from the original VUS report to reclassification was reported as roughly 49 to 50 months, and 64.6 months for the variants that became pathogenic or likely pathogenic. The authors suggested regular review of VUS at intervals of no more than three years. Because the pathogenic reclassifications took longest to surface, a lab that reviews on a slow cycle risks delaying precisely the notifications that matter most. The authors also reported 95.2 percent concordance with ClinVar for the 21 variants already reported there without conflicts, which supports using public submissions as a cross-check. Note that this is a single-centre series, so the rates are illustrative rather than universal.
What ACMG expects from laboratories
Two 2019 ACMG statements in Genetics in Medicine frame laboratory expectations. The first, on patient recontact after revision of genomic test results, describes recontact as fundamentally a shared responsibility among the ordering provider, the testing laboratory, and the patient. Within that sharing, the responsibility to inform the ordering physician of a variant reclassification sits with the laboratory. The statement also acknowledges there is no consensus on when or how often labs should review a variant, and it defers laboratory protocols to separate ACMG guidance.
The second statement, on reevaluation and reanalysis of genomic test results, is more operational. It recommends that labs keep separate policies for initial variant classification, variant-level reevaluation, and case-level reanalysis, and review those policies periodically. It advises prioritising variants by clinical impact, with uncertain and likely pathogenic variants reviewed more often than benign or likely benign ones, and reassessing variants classified under pre-2015 standards against current ACMG standards. When reclassifications may affect clinical management, such as uncertain to likely pathogenic, they should be communicated first.
It further recommends that labs respond to external requests for reevaluation, issue an addendum to the original report where appropriate, and have a policy for sending updated reports when the ordering provider is no longer involved in the patient's care. Labs should also submit classifications and reclassifications, with supporting evidence, to public databases such as ClinVar. For the ordering side of the relationship, see our overview of ACMG secondary findings reporting for labs.
Building a defensible reclassification workflow
The following elements translate the published expectations into process. They are a framework drawn from the sources above rather than a regulatory requirement, and your medical director and compliance lead should adapt them to your CLIA, state, and accreditation obligations. Director responsibilities in particular are covered in our article on CLIA lab director and personnel rules for genetic labs.
First, inventory your VUS. You cannot prioritise what you cannot query. Maintain a searchable record of every reported VUS and LP variant, with the classification date, the evidence version, and the ordering provider of record. Second, tier by clinical impact, following ACMG's guidance that uncertain and likely pathogenic variants warrant more frequent review. Third, set a review cadence you can defend and actually meet; the three-year interval suggested in the BRCA1/2 series is a reasonable reference point for high-priority genes, not a mandate.
Fourth, define triggers in addition to the calendar. New ClinVar submissions, gene-specific guideline updates, and new gene-disease evidence can justify an off-cycle review. Fifth, write the notification path. Specify who is notified, how, how the notification is documented, and what happens when the ordering provider has left the practice. Sixth, make the consent language and the report language say plainly that classifications may change, as ACMG recommends. Finally, track your own metrics: the number of variants reviewed per quarter, reclassifications issued, direction of change, and time from trigger to notification.
Billing and cost considerations
Reevaluation consumes bioinformatician, geneticist, and director time. ACMG's reevaluation statement says additional charges may be justified for professional reevaluation work and that payer coverage is needed for long-term sustainability. The source does not identify a specific CPT code or a Medicare coverage rule for unprompted reclassification, and we are not aware of one cited in these sources, so labs should treat proactive re-review as an operating cost unless a contract or policy says otherwise. Where a clinician requests case-level reanalysis, confirm in advance whether the request is a new billable service, and be careful with unlisted-code use; see our guide to CPT 81479 unlisted molecular code denials.
How ScreenMyGene helps
Recontact programs fail when the underlying test, indication, and ordering-provider data are scattered. ScreenMyGene helps ordering clinicians and laboratories keep structured records of what was ordered and why, which makes later reclassification notices easier to route. Learn more on the ScreenMyGene homepage.
Frequently asked questions
What is a VUS reclassification?
A VUS reclassification is a laboratory's revised interpretation of a variant of uncertain significance after new evidence, such as population data, functional studies, or segregation data, changes its ACMG/AMP category. The variant may move to benign, likely benign, likely pathogenic, or pathogenic, which can change clinical management for the patient and family.
Who is responsible for recontacting the patient?
ACMG describes recontact as a shared responsibility among the ordering provider, the testing laboratory, and the patient. The laboratory's core duty is to inform the ordering physician when a variant is reclassified. The ordering clinician then makes reasonable efforts to reach the patient, but cannot promise recontact will occur.
How often should a laboratory re-review VUS?
ACMG states there is no consensus on how often. Its reevaluation statement says uncertain and likely pathogenic variants warrant more frequent review than benign or likely benign ones. A single-centre BRCA1/2 series suggested a review cadence of no more than three years for regular VUS review.
Do most VUS get upgraded to pathogenic?
No. In the ClinVar analysis by Harrison and Rehm, 74.6 percent of reclassified VUS moved to likely benign or benign, and 25.4 percent moved to likely pathogenic or pathogenic. In the BRCA1/2 single-centre series, 94.8 percent of reclassified VUS moved to benign or likely benign.
Can a laboratory charge for reevaluation work?
ACMG's reevaluation statement notes that additional charges may be justified for professional reevaluation work, and that payer coverage is needed for long-term sustainability. Labs should confirm payer and contract terms before billing, because this document does not establish a specific billing code or coverage rule for reclassification.
Disclaimer: This article is for educational purposes only and is intended for laboratory, clinical, and revenue cycle professionals. It is not medical, legal, or compliance advice and does not establish a standard of care. Confirm requirements with your accrediting body, medical director, and counsel.
Sources: Harrison SM, Rehm HL. Is "likely pathogenic" really 90% likely? Reclassification data in ClinVar. Genome Medicine 2019;11:72; Innella G et al. Clinical implications of VUS reclassification in a single-centre series from application of ACMG/AMP classification rules specified for BRCA1/2. Journal of Medical Genetics 2024;61(5):483; David KL et al. Patient re-contact after revision of genomic test results: points to consider, ACMG. Genetics in Medicine 2019;21:769-771; ACMG. Points to consider in the reevaluation and reanalysis of genomic test results. Genetics in Medicine 2019.