Programs that work for you

"They are rigorous, they’re about making sure our labs, personnel, and test methods conform, that they’re in compliance. They’re independent, not driven by a vendor or a construction company.”

California Department of Transportation

Philip Stolarski, Former Deputy Division Chief, DES-METS & GS 

55+ years of experience
PSP participants
samples shipped per year
laboratory assessments per year
accredited labs


Proficiency Sample Reenrollment Fee

Aug 30, 2022

We have begun to process the annual invoices for active participants in the Proficiency Sample Program (PSP). This is an invoice for your upcoming year’s (2023) enrollment subscriptions.

Participants that do not pay their invoice within 30 days of receipt will have their enrollment cancelled. Because of the amount of time it takes our staff to reenroll participants, if your lab’s enrollment is cancelled and needs to be reenrolled, you will be charged a fee of $100. If your lab is AASHTO Accredited, failure to pay invoices on time may also result in suspension of your laboratory's accreditation status.

You should expect a hard copy of your annual PSP invoice to be sent to your account’s listed billing address in the next two weeks. International participants, or those who’ve made previous arrangements, will be notified via email. All customers currently have digital access to their PSP invoices by logging in your account. Payments can be made online via

Please direct any questions regarding PSP invoices or enrollments to