Washington prejudgment interest rate
United States Washington’s general prejudgment reference and qualifying medical-debt cap.
→ All Washington judgment & prejudgment interest rates
Fixed by statute
2026 Washington prejudgment interest at a glance
- Current rate
- 12% per year
- Effective date
- July 9, 2026
- Controlling authority
- RCW 19.52.010(1)
- Rate basis
- Fixed by statute
- Source checked
- July 9, 2026
- Recorded history
- 1 data point
Washington’s general legal-rate reference under RCW 19.52.010 can be 12% for a qualifying liquidated or readily determinable claim. Qualifying medical debt is capped at 9%, so the 12% figure is not universal. A written agreement or another statute can also control.
When Washington prejudgment interest applies
Prejudgment interest is available ONLY on LIQUIDATED or readily-determinable claims — those where the evidence furnishes data that makes it possible to compute the amount with exactness, without reliance on opinion or discretion (Prier v. Refrigeration Eng'g; Hansen v. Rothaus). It is BARRED on UNLIQUIDATED claims requiring jury/court discretion or opinion evidence to fix the amount.
When it starts accruing
Prejudgment interest accrues from the date the claim became liquidated / the amount became due and determinable (i.e., the date the liquidated sum could be computed), running until entry of judgment.
Simple or compound
The general branch is treated as simple interest, but the governing agreement, medical-debt cap, and any special statute must be checked before calculation.
→ Compare with the Washington post-judgment interest rate (interest after judgment)
Prejudgment interest under RCW 19.52.010(1) — 12% (simple interest). This is PREjudgment interest (accruing before entry of judgment) and is separate from Washington’s post-judgment rate; availability is limited by claim type (see the page). Verify against the statute text. Not legal advice.
Current recorded observation
| Effective date | Rate | Basis |
|---|---|---|
| July 9, 2026 | 12% | Statute |
Source & provenance
Observation recorded July 9, 2026 (00:00 UTC) from the cited source (Washington — app.leg.wa.gov):
https://app.leg.wa.gov/rcw/default.aspx?cite=19.52.010
Cite this page
StatuteRates. “Washington Prejudgment Interest Rate.” StatuteRates.com. Accessed today. https://statuterates.com/rates/washington-prejudgment-rate/ Rate recorded under RCW 19.52.010(1), effective July 9, 2026.