Stipulating to Liability Does Not Start Prejudgment Interest: Mahoney v Brockbank and CPLR 5002

Key Takeaways

• In Mahoney v Brockbank, the Second Department held that a stipulation as to liability does not trigger the accrual of prejudgment interest under CPLR 5002.
• Because the parties’ stipulation was silent on interest, prejudgment interest ran only from the later jury verdict on damages.
• In a long-delayed case, the difference can be enormous — at New York’s 9% statutory rate, years of forgone interest on a six-figure verdict is real money.
• The fix is contractual: plaintiffs accepting a liability concession should insist the stipulation expressly provide that interest accrues from its date.

Understanding Prejudgment Interest When Liability is Stipulated

In personal injury litigation, defendants sometimes agree to stipulate to liability early in the case, essentially admitting fault while reserving the right to contest damages. While this might seem advantageous to plaintiffs by streamlining the legal process, a New York appellate court decision highlights a critical financial consideration that attorneys must understand.

The Second Department’s ruling in Mahoney v Brockbank addresses a fundamental question: does a stipulation to liability trigger the accrual of prejudgment interest under New York law? The answer has significant implications for case strategy, particularly in cases involving substantial damages and lengthy litigation timelines. Understanding how prejudgment interest calculations work becomes crucial when evaluating whether to accept liability stipulations.

The Decision

Jason Tenenbaum’s Analysis:

Mahoney v Brockbank, 2016 NY Slip Op 05630 (2d Dept. 2016)

“In short, we conclude that a stipulation as to liability does not trigger the accrual of prejudgment interest under CPLR 5002. Moreover, because the parties did not provide for prejudgment interest in their stipulation, the Supreme Court properly determined that prejudgment interest was to be computed from the date of the jury verdict on the issue of damages.”

When I read this case, all I thought is a rear-end collision with serious injuries and a defendant stipulating to liability; the case takes 6 years to get to trial; and now, the plaintiff lost 54% interest on a case worth between $400,000-$800,000. Is that stipulating away to malpractice?

The Legal Framework: CPLR 5002 and the 9% Clock

CPLR 5002 governs interest “from verdict, report or decision to judgment”: interest is recoverable on the total sum awarded from the date the verdict was rendered or the report or decision was made. CPLR 5004 sets the statutory rate at nine percent per annum. In a bifurcated tort case, the long-settled rule is that interest runs from the decision establishing liability, even though damages are quantified later — the theory being that once fault is fixed, the defendant is holding money that belongs to the plaintiff.

Plaintiffs’ lawyers had a plausible argument that a liability stipulation is the functional equivalent of a liability verdict: the defendant has conceded fault, so the interest clock should start. Mahoney rejected the equivalence. A stipulation is a contract, not a “verdict, report or decision” within the meaning of CPLR 5002. Unless the parties write interest into their agreement, nothing has been “rendered” or “decided” that starts the statutory clock.

Why a Stipulation Is Not a Verdict

The distinction is more than formalism. A verdict or decision is an adjudication — a determination by a fact-finder or a court after contest. A stipulation is a bargain, and courts enforce bargains according to their terms. If the parties wanted interest to run from the stipulation date, they could have said so; the Second Department pointedly noted that “the parties did not provide for prejudgment interest in their stipulation.”

That contract framing cuts both ways. It denies plaintiffs an automatic interest windfall, but it also hands them a complete drafting solution. The court is not saying interest can never run from a liability concession — it is saying the parties must negotiate for it.

The Malpractice Math

Consider the scenario flagged in the original post: a serious-injury rear-end case where the defendant stipulates to liability, then the matter sits six years before a damages trial. At 9% simple interest, six years is 54% of the eventual award. On a verdict between $400,000 and $800,000, the silent stipulation costs the client roughly $216,000 to $432,000.

Worse, the stipulation removed the defendant’s incentive to push the case to trial. Once interest is not running, delay is free — every adjournment is interest the carrier never pays. A liability concession that looked like a plaintiff victory quietly became a defense financing strategy.

Practice Pointers

• Plaintiffs: never accept a bare liability stipulation. Insist on a clause that prejudgment interest under CPLR 5002 accrues from the date of the stipulation (or the date liability would otherwise have been tried).
• If the defense refuses the interest clause, reconsider the stipulation. Trying liability — particularly in a rear-end or other strong-liability case — preserves the interest start date a verdict provides.
• Defense counsel and carriers: Mahoney is leverage. A liability concession without an interest provision shifts the entire cost of court delay onto the plaintiff.
• Document the timeline. Where interest disputes arise, the dates of stipulation, note of issue, and verdict control the arithmetic; build a clean record.
• Watch the changing landscape for auto cases. New York’s May 27, 2026 tort reform (S9008-C/A10008-C, Part EE) eliminated the 90/180-day serious-injury category and added a greater-than-50% fault bar for Article 51 auto cases commenced on or after the effective date — changes that will reshape when defendants are willing to concede liability at all. See our analysis of the 2026 tort reform legislation.

Frequently Asked Questions

Does prejudgment interest start when the defendant admits liability in New York?

Not automatically. Under Mahoney v Brockbank, a stipulation to liability is not a “verdict, report or decision” under CPLR 5002, so interest does not begin to accrue unless the stipulation itself says it does.

What is the prejudgment interest rate in New York personal injury cases?

CPLR 5004 sets the statutory rate at 9% per annum. In tort cases, interest under CPLR 5002 runs from the liability determination to entry of judgment — which is why the start date matters so much in long-running cases.

How can a plaintiff protect interest when accepting a liability stipulation?

Negotiate an express term: the stipulation should state that prejudgment interest accrues from the stipulation’s date. Because the stipulation is enforced as a contract, the written term controls — silence forfeits the interest.

Related Resources

• Is it three years or 6 years? — the firm’s cluster hub on civil procedure timing traps
• Use the Israel form databank when in doubt
• Interest.
• Case remanded to Civil Court to determine whether interest was tolled
• Inability to pay will not allow vacatur of stipulation
• Browse the firm’s Legal Encyclopedia for more on damages and procedure
• Long Island Car Accident Lawyer