Generally, post-judgment interest starts to run on a civil judgment from the date the judgment is entered by the Court. In some courts, the entry of judgments is a function of the Court's Clerk. So even if a judge signs a judgment on one day, but the Clerk does not "enter" it until a week later, the post-judgment interest would not start to run until the judgment is docketed by the Clerk. When a judgment is considered entered is a product of the civil procedural rules and law applicable to the particular court from which the judgment was issued.
What post-judgment interest rate applies under state law?
At least in New York state, rate of post-judgment interest is set by the civil procedural law titled the Civil Practice Law and Rules (the "CPLR"). CPLR A? 5004 fixes the post-judgment rate of interest at 9% per year and CPLR A? 5003 states that interest shall run from the date of entry of the judgment. Many other states have statutes or rules that fix the post-judgment rate of interest as well. In New York and many other states, the interest is calculated as simple interest and not compounded. There may be states where the applicable rate fluctuates, as with the rate of post-judgment interest on civil judgments entered in the United States District Courts.
What interest rate applies in federal courts?
28 U.S.C. 1961 provides, in pertinent part, "interest [on a civil judgment] shall be calculated from the date of the entry of the judgment, at a rate equal to the weekly average 1-year constant maturity Treasury yield, as published by the Board of Governors of the Federal Reserve System, for the calendar week preceding the date of the judgment." Each Monday the Federal Reserve publishes the applicable rates for the prior week. A link to the current rate may be found here: http://www.federalreserve.gov/releases/h15/current/. In contrast to many states, e.g. New York, post-judgment interest on a federal civil judgment is compounded.
When is a party entitled to pre-judgment interest?
It depends. I know this is not particularly satisfactory answer. Whether a party is entitled to pre-judgment interest is a complicated question hinging on the facts of a particular case, the claims asserted by the parties and the applicable law and rules of the court in which the dispute has been brought. As a result, I do not take up the subject here, but will be explore it in a future legal guide.
Additional resources provided by the author
The foregoing is provided for informational purposes only and should not be construed as legal advise. I always encourage people to confer with qualified counsel admitted to practice in the jurisdiction in which the matter arises. The websites below may also be informative on this topic.