U.S. amends Korean welded line pipe AD order after CIT ruling

What changed

The investigation covered October 1, 2013 through September 30, 2014, and the order was published on December 1, 2015. The litigation centered on the Cohen's d test in Commerce's differential pricing analysis.

In Stupp IV, the Federal Circuit held that Commerce had not shown that SeAH's U.S. pricing data met statistical criteria SeAH identified as necessary for a reasonable use of that test, and directed an analysis consistent with Marmen.

In its fourth remand redetermination, dated March 16, 2026, Commerce dropped the Cohen's d test, adopted a 'price difference test' and stopped using the mixed comparison method. The CIT sustained it on September 15, 2026 in Court No. 15-00334.

SeAH keeps its current cash deposit rate because a later administrative review superseded it. The new all-others deposit requirements remain in effect until further notice.

The notice does not restate the earlier margins, which are in the November 10, 2015 amended final determination, or the scope, and it gives no liquidation or assessment instructions.

What an import team should check

• Identify the producer and exporter of your Korean welded line pipe: the notice amends only SeAH Steel Corporation's margin (4.55%) and the rate for all other producers and exporters (5.39%).
• Ask your customs broker when CBP's revised all-others cash deposit instructions apply to your entries, since the notice is applicable September 25, 2026 but does not give an entry date for them.
• Confirm that entries from SeAH keep SeAH's current cash deposit rate, which comes from a later administrative review and is not changed by this notice.
• Check product coverage against the December 1, 2015 antidumping duty order, because this notice does not describe the scope or list HTSUS lines.