What is priority in patent applications?

Priority in patent applications refers to the ability of a later-filed application to claim the benefit of, or priority to, an earlier-filed application. This allows the later application to effectively have the filing date of the earlier application for certain purposes.

According to the MPEP, “Under certain conditions and on fulfilling certain requirements, a later-filed application for patent filed in the United States may claim the benefit of, or priority to, a prior application filed in the United States (see 35 U.S.C. 119(e), 120, 121, 365(c), and 386(c); see also 37 CFR 1.78) or in a foreign country (see 35 U.S.C. 119(a)-(d) and (f), 365(a) and (b), and 386(a) and (b); see also 37 CFR 1.55).”