WASHINGTON—The Senate may vote Wednesday on a legislative amendment that would extend federal COBRA health insurance premium subsidies to employees laid off from April 1 through May 31.

The amendment, which Finance Committee Chairman Max Baucus, D-Mont., introduced Tuesday on the Senate floor, would replace a provision in the underlying bill, H.R. 4851. The existing provision would extend the 15-month, 65% federal premium subsidy to involuntarily terminated employees from April 1 through April 30.

The last short-term extension expired March 31.

On the Senate floor, Sen. Baucus said a longer extension is needed to allow time to work out an agreement on another measure, H.R. 4213, which would extend the subsidy to employees laid off through Dec. 31. The Senate previously approved that measure, but the House has yet to act on it.

“This amendment will extend…all the provisions in the current bill for one more month to give us time to work out a solid understanding so that, in the end, we can pass” the longer-term COBRA subsidy extension, Sen. Baucus said.

If the Senate approves the amendment, the measure would have to go back to the House, which has approved an extension only through April 30.