ASL interpretation in institutional settings has structural differences from spoken-language interpretation that affect both scheduling and how assignments are staffed.
Certification. The dominant national certification is the RID NIC (National Interpreter Certification), which has Performance, Knowledge, and Ethics components. Specialty certifications include CDI (Certified Deaf Interpreter: Deaf signers who work in teams with hearing ASL interpreters for complex or specialized communication), SC:L (Specialist Certificate: Legal), and the older CI/CT and OIC certifications still recognized for currently-credentialed interpreters.
Team interpreting. ASL interpreters typically work in pairs for assignments over an hour, switching every 15-20 minutes to manage the physical and cognitive load. Single-interpreter long assignments are non-standard and most professional associations consider them unsafe practice. Buyers should expect to book two interpreters for multi-hour assignments and budget accordingly.
On-site is the standard for ASL. Sign language is visual and embodied, so physical presence carries information that matters: clear sightlines, full use of space, and the ability to read and be read without the friction of a screen. For high-stakes encounters in particular — medical, legal, mental health — an interpreter in the room is what effective communication requires.
Deaf and DeafBlind patients. Some Deaf patients use tactile interpretation (interpreter signs into the patient’s hands), pro-tactile ASL, or other modalities for DeafBlind communication. These are specialized skills outside standard ASL interpreting. Booking interpreters for DeafBlind patients should specify the patient’s preferred mode in advance.
Federal and state law. ASL interpretation in healthcare is explicitly covered by Section 1557 AND by the ADA (Americans with Disabilities Act), which provides additional enforcement avenues including private rights of action that Section 1557 doesn’t.