A: NVLAP is an International Laboratory Accreditation Cooperation (ILAC) signatory and has been the sole accreditation service provider to the State Laboratory Program for nearly 30 years. Together with its NIST partner Office of Weights and Measures (OWM), NVLAP provides metrologically sound and consistent accreditation services that promote uniformity across the state metrology laboratories. Additionally, a state metrology laboratory can qualify for federal (OWM) subsidy of the NVLAP On-Site Assessment Fee (up to a $14,000 value) with prior OWM recognition of the laboratory’s capabilities.
Further benefits of a NVLAP accreditation (ISO/IEC 17025) of a calibration laboratory include:
Use of NIST Handbook 105-2, which includes specific requirements for legal metrology
Use of NIST Handbook 143, which utilizes a checklist to harmonize between the OWM laboratory recognition program and the NVLAP accreditation service
Access to experienced assessors with expert knowledge of NIST Handbook 143 and all metrology areas relevant to the state labs’ calibration and measurement capabilities.
Many state metrology laboratories require accreditation to ISO/IEC 17025 based on the needs of their customers utilizing their calibration services.
Accreditation provides international recognition of a state’s calibration services and strengthens the overall U.S. measurement system. Accreditation by NVLAP is also strongly encouraged by NIST OWM as it provides the most robust assessment of a laboratory’s legal metrology measurement capabilities (see prior Q&A). Notably, most state laboratories that achieve recognition status through the OWM Laboratory Recognition Program are then successfully accredited by NVLAP.
State laboratories that are recognized by OWM can also qualify for a direct subsidy of the NVLAP On-Site Assessment Fees (up to a $14,000 value). This may provide significant savings in overall costs for the states that are required to procure accreditation services. Please contact NVLAP directly (nvlap [at] nist.gov (nvlap[at]nist[dot]gov)) for an estimate of On-Site Assessment Fees, which are based on legal metrology requirements (NIST HB 105-2 and NIST HB 143). This information may also be used as documentation to support a procurement process to obtain an accreditation service.
Yes. In addition to NVLAP, there are five (5) other U.S. ABs that are ILAC signatories that provide assessment and accreditation of calibration laboratories (using ISO/IEC 17025): A2LA, ANAB, IAS, NVLAP, and PJLA. Most economies around the world possess only a single AB to cover calibration services within their national system. Thus, the U.S. is unique in having multiple ABs to provide such services. Please see further information here.
Yes. A state laboratory can continue to ensure SI traceability of their calibration services through successful recognition in OWM’s State Laboratory Program (based on NIST Handbook 143) and successful participation in the proficiency testing (PT) program.
No. It is the state laboratory’s legal responsibility/authority to evaluate any out-of-state calibration service supplier for SI traceability, which includes (but not limited to) realization to the SI units, unbroken chain of calibrations, calibration program (including proper handling and calibration intervals), documented uncertainties and procedures, technical competence of staff, and good measurement assurance practices (see NISTIR 6969 GMP 13). This is especially important for a laboratory calibration service supplier that is not active or a member of the NIST Handbook 143 State Laboratory Program (i.e., recognition) or accredited by a new to legal metrology non-NVLAP accreditation service outside of the NIST Handbook 143 program.
Historically, NIST OWM has provided 100 % subsidy for all costs for all state metrology laboratories to apply for and obtain NVLAP accreditation. This has included both the annual NVLAP Administrative/Technical Support Fee and the On-Site Assessment Fee, the latter of which is dependent on the individual scope of the state’s metrology program.
Effective April 1, 2024, NIST OWM will enact a new policy and provide support for only the On-Site Assessment Fee portion of the overall NVLAP accreditation fees. Thus, each state metrology laboratory program will be responsible for covering the costs for the annual NVLAP Administrative/Technical Support Fee. The current NVLAP Fee Structure is provided here.
The total amount of financial support for each laboratory is variable and depends on the scope of the individual state laboratory’s program and associated charges per the on-site assessment. The following table illustrates the range of fees for 2024:
Calibration and Measurement Capabilities
Admin/Technical Support Fee
On-Site Assessment Fee
Mass, Volume, Time
Mass, Volume, Temperature
Mass, Volume, Length, Time, Temperature
NIST OWM will continue to provide full support for the NVLAP On-Site Assessment fee towards laboratory accreditation.
The current NVLAP Fee Structure is provided here.
The current NIST OWM policy is provided here. Any updates to this policy will be provided on this webpage.
Additionally, OWM will notify state metrology laboratories of any further updates through various communication methods, including (but not limited to) email and listserv announcements to State Directors, individual phone calls to affected state laboratories, OWM newsletter articles, and via OWM Laboratory Metrology Info Hours.