Castro v. Lemus, 456 P.3d 750

Mother married Husband in 2012; Husband later spent time in Mexico and the couple separated for a period.
During the separation Mother had a relationship with Castro and conceived a child; Husband returned and the child was born while Mother and Husband remained married.
Under the Utah Uniform Parentage Act (UUPA) Husband is a "presumed father" because the child was born during the marriage.
Castro (an alleged/biological father) filed to adjudicate paternity, custody, support, and parent-time; Mother moved to dismiss for lack of standing citing R.P. v. K.S.W. and UUPA § 78B-15-607(1).
The district court dismissed; the court of appeals certified constitutional questions and the Utah Supreme Court granted review.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Does the UUPA grant standing to an alleged father to adjudicate paternity when a presumed father exists?	Section 78B-15-602(3) expressly grants standing to "a man whose paternity of the child is to be adjudicated"—this includes Castro; §607(1) is a timing rule and does not strip standing.	§78B-15-607(1) should be read to limit who may raise paternity when a presumed father exists (mother, presumed father, and support agency); R.P. supports denying standing to other alleged fathers.	The Court holds §602 grants standing to alleged fathers and §607(1) imposes timing limits for certain parties but does not revoke standing. Overrules R.P. and reverses dismissal.
If §607(1) were read to deny standing, would that interpretation present constitutional problems?	Castro contends a denial of standing would violate procedural and substantive due process and equal protection.	Mother argues policy (protecting marriage, finality) justifies §607(1) as limiting challenges.	The Court avoids the constitutional question by adopting the statutory interpretation that avoids raising serious constitutional doubts; it did not decide the constitutional claims.

R.P. v. K.S.W., 320 P.3d 1084 (Utah Ct. App. 2014) (court of appeals precedent holding limited standing under §607 later overruled)
Hudgens v. Prosper, Inc., 243 P.3d 1275 (Utah 2010) (standard of review for motion to dismiss)
Bagley v. Bagley, 387 P.3d 1000 (Utah 2016) (statutory interpretation—ascertaining legislative intent)
Waite v. Utah Labor Comm’n, 416 P.3d 635 (Utah 2017) (review of statutory interpretation and constitutionality)
Marion Energy, Inc. v. KFJ Ranch P’ship, 267 P.3d 863 (Utah 2011) (use of other modes of statutory construction when language ambiguous)
Troxel v. Granville, 530 U.S. 57 (U.S. 2000) (parental liberty interest in care, custody, and control of children)
Lehr v. Robertson, 463 U.S. 248 (U.S. 1983) (biological link alone does not guarantee constitutional protection; opportunity to develop relationship is key)
In re Adoption of T.B., 232 P.3d 1026 (Utah 2010) (due process satisfied by providing unwed biological fathers meaningful chance to preserve relationship)