To sell an external power supply in the United States, it has to meet the Level VI efficiency standards for external power supplies set by the U.S. Department of Energy (DOE) under the Energy Policy and Conservation Act. That means the unit must clear a minimum active-mode efficiency, stay under a maximum no-load power draw, be tested using the DOE’s Uniform Test Method, and be certified through the DOE’s Compliance Certification Management System before it enters U.S. commerce. These requirements have applied to every covered power supply manufactured on or after February 10, 2016.
What Counts as a Covered External Power Supply
The rules reach any power conversion circuit in its own separate enclosure that plugs into a wall outlet and converts household AC into lower-voltage DC or lower-voltage AC to run a consumer product. The laptop brick and the small plug-in adapter for a wireless speaker are the everyday examples. The converter has to be physically separate from the product it powers; if it is built into the device, these rules do not apply.1eCFR. 10 CFR 430.2 – Definitions
USB Power Delivery chargers with a USB-C output are treated as external power supplies too, and the DOE has published specific test methods for how their nameplate output power is determined at different voltage levels.2Federal Register. Energy Conservation Program: Test Procedure for External Power Supplies
Three categories sit outside the definition entirely and do not need to meet these thresholds or be certified: LED and OLED lighting drivers, DC ceiling fan drivers, and commercial and industrial power supplies. Commercial and industrial units follow a separate DOE regulatory track, so if a converter is designed and marketed for commercial or industrial equipment rather than a consumer product, it is not a Level VI matter.3Department of Energy. External Power Supplies
Active Mode Efficiency Requirements
Active mode efficiency measures how much of the power drawn from the wall reaches the connected device as usable output. The thresholds live in 10 CFR 430.32(w) and vary with output power rating, whether the unit is basic-voltage or low-voltage, whether it is single-voltage or multiple-voltage, and whether it converts AC to DC or AC to AC.
For a single-voltage AC-to-DC basic-voltage supply, the framework runs like this:
- 1 watt or less output: efficiency must be at least 0.5 times the output power plus 0.16, expressed as a decimal.
- Above 1 watt up to 49 watts: efficiency follows a logarithmic formula tied to output power.
- Above 49 watts up to 250 watts: at least 88.0% efficient.
- Above 250 watts: at least 87.5% efficient.
Low-voltage and AC-to-AC models sit on slightly different curves. A low-voltage AC-to-DC unit in the 49-to-250-watt band must hit 87.0%, and a basic-voltage AC-to-AC unit in the same band must reach 88.0%. Multiple-voltage supplies have their own table with generally lower floors, such as 86.0% above 49 watts.4eCFR. 10 CFR 430.32 – Energy and Water Conservation Standards and Their Compliance Dates
No-Load Power Limits
The no-load standard caps how much power the supply may draw when it is plugged in but nothing is connected to its output. The applicable ceiling depends on category and output rating:
- Single-voltage AC-to-DC, basic or low-voltage, up to 49 watts output: no more than 0.100 watts.
- Single-voltage AC-to-DC, above 49 watts up to 250 watts: no more than 0.210 watts.
- Single-voltage AC-to-DC, above 250 watts: no more than 0.500 watts.
- Single-voltage AC-to-AC, basic-voltage: no more than 0.210 watts up to 250 watts, and no more than 0.500 watts above 250 watts.
- Multiple-voltage supplies: no more than 0.300 watts regardless of output.4eCFR. 10 CFR 430.32 – Energy and Water Conservation Standards and Their Compliance Dates
Testing Your Product
The numbers you certify to the DOE have to come from testing under the Uniform Test Method in Appendix Z to Subpart B of 10 CFR Part 430. Since February 15, 2023, that method is the required basis for all efficiency representations.5Legal Information Institute. 10 CFR Appendix Z to Part 430 – Uniform Test Method for Measuring the Energy Consumption of External Power Supplies
Testing is done on the power supply in its final production form, housing and output cord included. Units intended for U.S. operation are tested at 115 volts and 60 hertz, held within 1% of those values, with the ambient temperature controlled and documented. Measurement instruments have to meet the specified uncertainty and resolution requirements so that different labs produce consistent readings.5Legal Information Institute. 10 CFR Appendix Z to Part 430 – Uniform Test Method for Measuring the Energy Consumption of External Power Supplies
Certifying Through CCMS
Before you distribute a covered power supply in the United States, you have to certify each basic model through the DOE’s Compliance Certification Management System, an electronic filing portal.6eCFR. 10 CFR 429.12 – General Requirements Applicable to Certification Reports
The certification report identifies the model number, the measured active mode efficiency, the no-load power consumption in watts, and the nameplate output power, together with manufacturer contact information. Filing the report is a legal attestation that the model complies with the applicable federal energy conservation standards. A product cannot lawfully enter U.S. commerce until its report is on file.
Certification is not one-and-done. Manufacturers file updated reports on an annual cycle, and for external power supplies the annual deadline is September 1. Missing that date can trigger enforcement even when the product itself still meets the efficiency standards.7Department of Energy. Upcoming Annual Certification Date for CCMS
Recordkeeping Duties
Keep the full test report, the underlying measurement data, and the supporting records for at least two years after you notify the DOE that the model has been discontinued. If any ratings were generated using an alternative determination method under 10 CFR 429.70 instead of physical testing, records tied to that method must be retained for two years after every model relying on it has been discontinued.8eCFR. 10 CFR 429.71 – Maintenance of Records
Marking Compliant Products
Compliant power supplies typically carry a Roman numeral on the label under the International Efficiency Marking Protocol. A “VI” mark on the adapter or its packaging signals that the unit meets the current federal thresholds. Buyers, distributors, and enforcement staff use the mark as a quick compliance check, and it is often printed inside a circle alongside other regulatory symbols on the adapter’s label.
Penalties for Selling Non-Compliant Units
The DOE conducts market surveillance and can pull products from the shelf for verification testing at any time. If a unit fails to meet the efficiency levels it was certified to, the penalty is assessed per unit sold or offered for sale under EPCA. The statutory base penalty is adjusted for inflation each year, so the per-unit maximum climbs over time.9Department of Energy. Civil Penalties for Energy Conservation Standards Program Violations Policy Statement
The DOE’s stated policy is to seek the maximum penalty against manufacturers that knowingly distribute non-compliant products. For a high-volume SKU, a modest per-unit figure quickly reaches into the millions. The DOE can also require corrective action, including removal from the market. Failing to file the required CCMS certification report is a separate violation and can carry additional daily penalties.
What May Change Next
The DOE reviews these standards periodically and can tighten them when higher efficiency becomes cost-effective. Industry has been tracking possible Level VII standards that would raise active-mode efficiency floors and lower the no-load caps compared with Level VI. Separately, the DOE published a notice in May 2025 (90 FR 20831) proposing changes to the reporting requirements for exempt consumer external power supplies.3Department of Energy. External Power Supplies
If Level VII is finalized, a compliance lead time will follow before the new thresholds take effect. Redesigning a supply to meet tighter targets is not a quick change, so watch the Federal Register and the DOE’s buildings efficiency page and start engineering work before the final rule lands.