Metrc (Maine) Bulletin ME_IB_0069 (distributed 08/18/2026; effective 09/01/2026) explains new Metrc functionality that surfaces minimum lab sample size expectations during “Submit for Testing,” records the minimum at the time of sample creation in package history, and clarifies how minimums are calculated when submitting multiple samples from one source package. This article breaks down what changed, what warnings or errors you may see, and what it means for day-to-day sampling and testing workflows.
What changed in Metrc Maine: minimum lab sample size visibility
When you create a lab sample package using the “Submit for Testing” action, Metrc now displays a read-only Minimum Sample Size value on the action window. The minimum shown is determined by the applicable configuration for the item category (for example, “Buds”) and is matched to the source package unit of measure (UoM) when possible.
Operationally, this means staff can see Metrc’s minimum sample size expectation at the moment they are entering the lab sample quantity, instead of discovering issues later in testing coordination or audits.
Warning behavior: submitting below the minimum
If the lab sample quantity you enter is below the displayed minimum, Metrc will not automatically block the transaction. Instead, Metrc presents a confirmation warning stating that the sample quantity is below the minimum sample size and asks whether you want to continue.
This design is important for real-world operations where exceptions can occur, but it also creates a compliance accountability point: teams should document internal justification anytime they proceed below the displayed minimum to avoid confusion during investigations, OCP inquiries, or internal audits.
Package History now records the minimum at time of creation
Metrc records the applicable minimum sample size (as of the time the sample is created) in the Package History for transparency and traceability.
Practically, this helps compliance managers and inventory auditors answer questions such as: “What minimum was Metrc applying when this sample was made?” and “Did the facility knowingly proceed under the displayed minimum?”
Multiple samples from one source package: how the minimum is calculated
Metrc clarifies that when you create two lab samples from the same production batch package (for example, non-potency retesting), the minimum sample size for each lab sample is based on the original quantity of the source package, not the reduced quantity remaining after creating the first sample.
In practice, this prevents the minimum from shrinking as you pull sequential samples from the same batch, which supports consistent sampling expectations and reduces the risk of “gaming” sample-size thresholds by taking multiple smaller pulls.
Known limitation: pre-roll minimum sample size not yet calculable
Metrc notes that Pre-Rolls minimum sample size will not be calculable in Metrc at this time, but is expected to become available later in 2026. Operators should continue following Maine OCP testing and sampling rules and their lab’s sampling guidance for pre-roll categories until Metrc releases the calculation support.
Error condition: mismatched units of measure (UoM) without Unit Weight
If the sample package UoM differs from the source package UoM and no Unit Weight has been recorded for the sample package’s item, Metrc will display an error indicating the minimum sample size could not be calculated due to mismatched UoM with no Unit Weight.
Day-to-day impact: if your workflow involves converting between “Each” and “Grams” (or similar), ensure item setup includes Unit Weight where needed so Metrc can calculate minimum sample size correctly. Without proper item configuration, staff may be delayed at the “Submit for Testing” step and may need compliance or inventory admins to correct item records before sampling can proceed.
What Maine operators should change in daily workflows
Training and SOPs: Update sampling SOPs so staff always review the displayed “Minimum Sample Size” before continuing, and ensure escalation paths exist when the entered quantity is below the minimum.
Documentation discipline: If your team proceeds under the minimum after the warning, capture the reason in internal records (and in any note fields your SOPs require) so the decision is defensible later.
Item master data: Review item categories, UoM conventions, and Unit Weight setup to reduce “could not calculate” errors—especially for products tracked as “Each” that originate from weight-based packages.
Retesting planning: For non-potency retesting scenarios where multiple samples are needed from the same batch, plan quantities knowing that each sample’s minimum is based on the original batch size.
API update for integrators: lab sample size configurations endpoint
Metrc introduced a new Web API endpoint so third-party integrators can retrieve lab sample size configurations and align user interfaces, validations, and workflow prompts with what Metrc will display to end users.
Endpoint: GET /packages/v2/labsamplesizes
Integrators supporting Metrc Maine should review and update mappings and validations prior to the 09/01/2026 effective date to prevent discrepancies between ERP prompts and Metrc’s displayed minimum sample size and warning behavior.
Labeling and retail readiness: where Distru fits
While this bulletin focuses on sampling, operators should also keep packaging and labeling aligned with Metrc-driven workflows—especially as products move from tested inventory into retail-ready states.
DistruLabels: DistruLabels is a 100% free tool for creating compliant packaging and retail labels and can help teams stay aligned with Metrc Retail ID compliance by producing consistent, scannable labels that match the inventory records operators rely on in Metrc.
DistruERP: For larger operators needing end-to-end supply chain management, DistruERP is Distru’s comprehensive Cannabis ERP platform, designed to manage inventory, production, distribution, and compliance workflows that connect operational reality to Metrc reporting requirements.
Metrc support channels referenced in the bulletin
Metrc Support: Support is available through the Metrc Support portal or by calling 877-566-6506.
Support hours: • Monday – Friday, 8 a.m. ET – 10 p.m. ET
• Saturday 10 a.m. – 8 p.m. ET
• Sunday – Voicemail or portal only
Metrc Learn: On-demand training is available via Metrc Learn (accessible directly or through the Support menu in Metrc).
Metrc Expert: The in-app knowledge base is accessible via the widget icon in the lower right of Metrc.
API support: Integrators can contact Metrc API Support at api-info@metrc.com.
