NRS 126.051
Presumptions of paternity.
1.
A man is presumed to be the natural father of a child if:(a)
He and the child’s natural mother are or have been married to each other and the child is born during the marriage, or within 285 days after the marriage is terminated by death, annulment, declaration of invalidity or divorce, or after a decree of separation is entered by a court.(b)
He and the child’s natural mother were cohabiting for at least 6 months before the period of conception and continued to cohabit through the period of conception.(c)
Before the child’s birth, he and the child’s natural mother have attempted to marry each other by a marriage solemnized in apparent compliance with law, although the attempted marriage is invalid or could be declared invalid, and:(1)
If the attempted marriage could be declared invalid only by a court, the child is born during the attempted marriage, or within 285 days after its termination by death, annulment, declaration of invalidity or divorce; or(2)
If the attempted marriage is invalid without a court order, the child is born within 285 days after the termination of cohabitation.(d)
While the child is under the age of majority, he receives the child into his home and openly holds out the child as his natural child.2.
A conclusive presumption that a man is the natural father of a child is established if tests for the typing of blood or tests for genetic identification made pursuant to NRS 126.121 show a probability of 99 percent or more that he is the father except that the presumption may be rebutted if he establishes that he has an identical sibling who may be the father.3.
A presumption under subsection 1 may be rebutted in an appropriate action only by clear and convincing evidence. If two or more presumptions arise which conflict with each other, the presumption which on the facts is founded on the weightier considerations of policy and logic controls. The presumption is rebutted by a court decree establishing paternity of the child by another man.
Source:
Section 126.051 — Presumptions of paternity., https://www.leg.state.nv.us/NRS/NRS-126.html#NRS126Sec051.