---
kind: "section"
citation: "37 C.F.R. § 42.108"
title: "37"
number: "42.108"
heading: "Institution of inter partes review."
url: "https://uscodex.org/cfr/37/42.108"
---

# §42.108. Institution of inter partes review.

- (a) When instituting inter partes review, the Board will authorize the review to proceed on all of the challenged claims and on all grounds of unpatentability asserted for each claim.
- (b) At any time prior to a decision on institution of inter partes review, the Board may deny all grounds for unpatentability for all of the challenged claims. Denial of all grounds is a Board decision not to institute inter partes review.
- (c) **Inter partes—** review shall not be instituted unless the Board decides that the information presented in the petition demonstrates that there is a reasonable likelihood that at least one of the claims challenged in the petition is unpatentable. The Board's decision will take into account a patent owner preliminary response where such a response is filed, including any testimonial evidence. A petitioner may seek leave to file a reply to the preliminary response in accordance with §§ [42.23](/cfr/37/42.23.md) and [42.24(c)](/cfr/37/42.24.md?p=c). Any such request must make a showing of good cause.

## Notes

### Amendments

[85 FR 79129, Dec. 9, 2020]

### Source

Source: 77 FR 48727, Aug. 14, 2012, unless otherwise noted.

### Authority

Authority: 35 U.S.C. 2(b)(2), 3, 6, 21, 23, 41, 134, 135, 143, 153, 311, 312, 314, 316, 318, 321-326, 328; Pub. L. 112-29, 125 Stat. 284; and Pub. L. 112-274, 126 Stat. 2456.

### Source

Source: 77 FR 48669, Aug. 14, 2012, unless otherwise noted.

### Amendments

[85 FR 79129, Dec. 9, 2020]