The Ongoing Duty to Supplement Discovery
When you answer written discovery early in a lawsuit, your answers reflect what’s true on the day you sign them. But cases don’t stand still. You may get more treatment, your symptoms may change, or new evidence may come into your file months later. Washington’s rules don’t expect your original answers to freeze the case in place — they expect the record to keep up with reality. That’s the job of supplementing discovery, and understanding it helps you play your part well.
Disclaimer: This post is intended for general informational purposes only and does not constitute legal advice. For guidance specific to your situation, please consult with a qualified personal injury attorney.
Your Answers Are a Snapshot in Time
Interrogatory answers are accurate as of the date you sign them — not forever. In many cases, you’ll answer discovery relatively early, and then the case continues for many more months. During that stretch, plenty can change. You might seek additional medical care. Your team might retain an expert who generates a report. New photos, records, or bills might come into the file. None of that was known when you first answered, so your original responses can become incomplete or inaccurate over time.
There Is a Continuing Duty to Supplement
Here’s the part that surprises many people: keeping your answers current isn’t optional, and it doesn’t depend on the other side asking again. Once a party has answered discovery, the party must seasonably supplement or correct the response when later-acquired information makes the earlier answer incomplete or inaccurate — for example, new treatment, additional bills, changed symptoms, newly discovered witnesses, or updated expert opinions. “Seasonably” means reasonably promptly once you learn the new information, not on the eve of trial. The duty runs on its own; you don’t wait for a renewed request from the defense to trigger it.
That distinction matters, because the consequences of ignoring it are real. A party that fails to supplement when it should have can face terms or other sanctions from the court — and, as a practical matter, may be barred from using the withheld information later. In other words, sitting on a development that makes an earlier answer misleading isn’t a neutral choice; it can hurt your case. Keeping the record current protects you.
What Kinds of Updates Trigger It
The developments that most often call for supplementation are practical ones:
- A new round of treatment, or resumed care after a gap.
- A change in symptoms — improvement or worsening.
- Additional medical bills or out-of-pocket costs.
- Newly discovered witnesses with knowledge of your injuries or losses.
- Updated or newly generated expert opinions, reports, measurements, photographs, or video created during an evaluation.
Each of these may be new information that didn’t exist — or wasn’t known — when you first answered. Sometimes an answer even flags this at the outset, noting that a particular response “will be supplemented later” because the information wasn’t yet available. Those are natural items to revisit as the case develops.
How It Works in Practice
The duty applies throughout the case as information comes in, but supplementing often becomes a particular focus near the discovery cutoff. Around that deadline, your attorney will usually take a fresh look at your earlier answers — checking for updated treatment, updated damages, newly retained experts, and any answer that was left open to be completed later. Where new material exists, the update may take the form of a supplemental disclosure of evidence (additional records, bills, photographs, videos, or expert materials) along with a supplemental interrogatory answer explaining what has changed. Both sides carry this same obligation, so you can expect the defense to be updating its answers too.
Your Part in the Process
You don’t have to track court rules to help here. What matters is keeping your legal team informed as things change. If you start seeing a new provider, resume treatment after a gap, develop new or worsening symptoms, incur new out-of-pocket costs, or learn of new information related to your case, let your attorney know. Those updates are the raw material for supplementing discovery, and passing them along promptly is what lets your attorney meet the duty on time rather than scrambling at the last minute.
Final Thoughts
Supplementing discovery comes down to one idea: once you’ve answered, you have a continuing duty to keep those answers accurate — seasonably correcting or updating them as later information comes in, whether or not the other side asks. Your answers were a snapshot; as the picture changes, the record on file should change too. Staying in close communication with your attorney is the simplest way to make sure your case rests on accurate, current information all the way through.
If your treatment or circumstances have changed while your case is pending, don’t keep it to yourself — reach out to our team so we can keep your case current. We’re here to help injured people throughout Washington navigate every stage of litigation.
