Can a supplemental amendment be filed after the close of prosecution?

Yes, supplemental amendments can be filed after the close of prosecution, but their treatment depends on the specific circumstances. According to MPEP 714.03(a):

Amendments filed after final rejection, after allowance, after an Office action that otherwise closes prosecution in the application, or after the filing of a notice of appeal are governed by 37 CFR 1.116.

The treatment of such amendments is as follows:

• After final rejection: The amendment may be entered if it places the application in condition for allowance or simplifies issues for appeal.
• After allowance: Amendments may be entered with the approval of the primary examiner, provided the amendment does not require substantial additional examination.
• After appeal: Amendments filed after the filing of a notice of appeal may be entered if the amendment overcomes all rejections under appeal and does not raise new issues.

In all cases, the examiner has discretion to enter or not enter the amendment based on the specific content and timing of the submission.

To learn more:

• supplemental amendment
• after final rejection
• after allowance
• after appeal