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Interpreters for Clinical Trials and Informed Consent

A person who does not read English can take part in research, but only if the consent information reaches them in a language they understand and the process is documented the way the regulations require. Here is what the rules say, where the interpreter fits in short form consent, and how a study team books interpreters for consent and follow-up visits.

The research team provides the interpreter, not the participant

Both sets of federal rules use the same words: the information given to the subject or their legally authorized representative has to be in language understandable to them (45 CFR 46.116 for HHS-funded research under the Common Rule, 21 CFR 50.20 for FDA-regulated trials). The duty to obtain consent belongs to the investigator, so arranging the interpreter is the study's job. A participant should never be asked to bring or pay for one.

FDA's 2023 informed consent guidance goes further. It recommends that investigators describe to the IRB, before initial review, how interpreters will be made available when they expect to enroll people who do not understand English; that the IRB approve procedures so translations are done by qualified people and interpretation is available; and that interpreter services be available throughout the research, not only at consent. It also notes that organizations receiving HHS financial assistance have Title VI obligations to people with limited English proficiency.

Who books us, then: research sites and study coordinators who need an interpreter for a consent visit or a run of follow-up visits in a language they cannot cover in house; sponsors and contract research organizations arranging language support across sites; and academic study teams running interviews or surveys with participants. Written translation of the consent form, the short form or study materials is a separate service, quoted per page.

Short form consent, step by step, and where the interpreter sits

When there is no translated long form, both rule sets allow a short form: a written document stating that the elements of consent were presented orally (45 CFR 46.117(b)(2), 21 CFR 50.27(b)(2)). In practice, following the regulations and FDA's guidance:

• The IRB approves a written summary of what will be said — often the English long form itself — and a short form in the participant's language.
• The person obtaining consent presents the information orally, through the interpreter. FDA says this may be an oral translation of the IRB-approved English long form. The interpreter renders it in full, then the participant's questions and the answers.
• A witness attends the oral presentation, in person or by phone or video, not just the signing. The witness may not be the person obtaining consent; FDA strongly recommends the witness be fluent in the language of the presentation and, if possible, not related to the participant.
• The interpreter may serve as the witness, but does not have to (FDA guidance, 2023). If your IRB's procedure uses the interpreter as witness, tell us when you request, so the interpreter expects to sign.
• Signatures: the participant signs the short form only; the witness signs the short form and the summary; the person obtaining consent signs the summary. The participant receives copies of both.

What a consent visit asks of an interpreter

A long consent form read aloud through an interpreter is sight translation followed by consecutive dialogue, and it is slow: everything is said twice, and the questions come after. The vocabulary is specific and easy to blur — randomization, placebo, blinding, study arm, adverse event, compensation for injury, the right to withdraw at any time without losing care. Each has to come across exactly, because the participant's decision depends on the difference between "you may receive the study drug" and "you will receive it."

The interpreter's job is to render, not to persuade or reassure. Participants often take the interpreter for a member of the care team and ask them directly whether they should join; the interpreter passes the question to the investigator. The risk the consent process exists to prevent — a participant who believes the study is treatment chosen for them — is easiest to miss when the explanation is coming through a third person, so the investigator should ask the participant to say back, through the interpreter, what will happen and what the alternatives are.

What goes wrong

• A family member interprets. In pediatric research FDA says the child who will take part should not interpret for the parent, even if fluent in English (FDA guidance, 2023). Relatives also have their own view of whether the participant should enroll.
• One person in two roles. A bilingual coordinator who presents the consent in the participant's language is the person obtaining consent, and so cannot also sign as the witness to the oral presentation.
• An interpreter at consent and nobody afterward. Follow-up calls, symptom diaries and adverse event questions are where participants with limited English get lost; FDA recommends interpreter services throughout the study.
• The wrong variety of the language. A short form in one variety of a language and an interpreter or participant from another can leave both of them unsure. Tell us the participant's country or region.
• No documents in advance. An interpreter who has seen the long form and the visit schedule renders a two-hour consent far more accurately than one meeting it cold.

Booking interpreters for a study

A consent visit in person usually fits the two-hour minimum at $110 an hour: $220, plus travel at $0.70 per mile from the interpreter's location. Follow-up visits and calls by video or phone are $80 an hour with a one-hour minimum, so a participant with six one-hour follow-up visits costs $480 in interpreting for the follow-up schedule. A full day of screening visits may need two interpreters in relay. Rates are per interpreter, per hour, from the scheduled start.

Send with the request: the language and the participant's region, the visit schedule, whether visits are in person or remote, the IRB-approved English long form and summary and the translated short form, a list of study terms, and whether the interpreter will act as witness. The interpreter does not need the participant's identifying details to prepare. Translating the consent form or other study documents is a separate written service; see clinical trial document translation.

By video, by phone or in person

Virtual interpreting runs on Zoom, Google Meet or Microsoft Teams, or over the telephone. It is quicker to arrange, costs less and carries no travel charge, and it suits appointments, calls and most meetings.

In person is what venues with their own rules tend to expect, and the right choice when documents are being signed or several people are speaking at once. Tell us the platform, or the city and the venue, when you send the request.

Languages

The standard-availability languages are: Spanish, Portuguese, French, Mandarin, Cantonese, Arabic, Russian, Korean, Vietnamese, Haitian Creole, Polish, Italian, German, Japanese, Hindi, Urdu, Persian, Turkish, Ukrainian, Tagalog, Bengali, Punjabi, Gujarati, Tamil, Armenian, Greek, Hebrew, Romanian, Serbian, Bosnian, Somali and Nepali. Every other language we offer carries the 25–30% limited-availability rate. If a language is not on that list it is not because we cannot do it — it is because the pool of qualified interpreters in the United States is small enough that we will not promise a date without checking.

Each language has its own page on what to watch for — dialects, names, dates, who the speakers usually are: see interpreters by language.

What it costs

Rates are per interpreter, per hour, and billed from the scheduled start time rather than from when everyone actually arrives.

• Virtual — $80 per hour, one-hour minimum. Zoom, Google Meet, Teams or telephone.
• In person — $110 per hour, two-hour minimum.
• Limited-availability languages — add 25–30%. Which languages those are is listed below rather than left vague.
• Travel for in-person work — $0.70 per mile from the interpreter's location.

How the travel charge works out

Travel is charged at $0.70 per mile from the interpreter's location, which means you can work it out rather than wait for a quote: a 20-mile round trip is $14, a 60-mile round trip is $42, a 150-mile round trip is $105. There is no separate call-out fee on top.

We will not pretend to know in advance where the interpreter will be coming from — that depends on the language, the date and the venue. What we do is confirm the interpreter and the exact travel figure before you book, so it is never a surprise on the invoice. Virtual assignments carry no travel charge at all, which is one reason most of what we do is virtual.

How booking an interpreter works

• You send the request with the form below: the language, the setting, the format, the date and how long it should last.
• We confirm before you commit: the interpreter, the exact price and the travel figure if there is one. We reply the same business day, and no payment is taken at this stage.
• You confirm, and the interpreter is booked for your date.

What to have ready

The more of this comes in the first message, the fewer exchanges before you have a price:

• The language, the date, the start time and how long it should run.
• Virtual or in person: the platform, or the city and the venue.
• The setting and the subject matter.
• How many people need interpreting for.
• Any credential the venue requires of the interpreter.

Request an interpreter

Tell us the date, the language and the setting and we will come back with the interpreter, the exact price and the travel figure if there is one — before you commit to anything.

Sources

What this page says about the rules was checked against these official sources on October 21, 2026. Rules change; the source is always the authority.

• 45 CFR 46.116 — General requirements for informed consent (Common Rule, eCFR current text)
• 45 CFR 46.117 — Documentation of informed consent, short form (eCFR current text)
• 21 CFR 50.20 — General requirements for informed consent (FDA, eCFR current text)
• 21 CFR 50.27 — Documentation of informed consent, short form (FDA, eCFR current text)
• U.S. Food and Drug Administration — Informed Consent: Guidance for IRBs, Clinical Investigators, and Sponsors (final, August 2023)

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