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Contact CLSI: Get in Touch with Us Today

We’d be happy to speak with you more about our products, programs, membership, and mission.

CLSI Address

Clinical and Laboratory Standards Institute
5 Great Valley Parkway
Suite 219
Malvern, PA 19355

Please send payments to:

Clinical and Laboratory Standards Institute
PO Box 645766
PITTSBURGH, PA 15264-5255

Please send overnight courier payments to:

PNC Bank C/O Clinical and Laboratory Standards Institute
Lockbox Number 645766
500 1ST AVE

Phone Numbers

P: +1.610.688.0100
F: +1.610.688.0700
Toll Free (US): 877.447.1888
Customer Service phone hours
8:30 AM–5:00 PM Eastern (US) Time

E-mail Us



Customer Service, Orders, and General Questions


Technical Questions

If you have technical questions regarding the content of CLSI standards and guidelines, please e-mail standard@clsi.org.