Can I claim priority to a foreign application after my U.S. patent has been issued?

Yes, it is possible to claim priority to a foreign application after your U.S. patent has been issued. According to MPEP 216.01, a claim for priority under 35 U.S.C. 119(a)-(d) or (f) can be made after the patent is granted, subject to certain conditions:

• The claim must be made within the time period set forth in 37 CFR 1.55(g).
• A petition to accept an unintentionally delayed claim for priority must be filed.
• The required fee must be paid.
• A certified copy of the foreign application must be submitted.

The MPEP states: ‘A claim for priority under 35 U.S.C. 119(a)-(d) or (f) for the benefit of a prior foreign application may be made after the patent issues if the claim is accompanied by a grantable petition to accept an unintentionally delayed claim for priority.’