Colo. Rev. Stat. § 19-4-105 (2026)

(1) A person is presumed to be the natural parent of a child if: (a) The person and the parent who gave birth to the child are or have been married to each other or are in a civil union pursuant to article 15 of title 14, and the child is born during the marriage or civil union, within three hundred days after the marriage or civil union is terminated by death, annulment, declaration of invalidity of marriage or civil union, dissolution of marriage or civil union, or divorce, or after a decree of legal separation is entered by a court; (b) Before the child's birth, the person and the parent who gave birth to the child have attempted to marry each other by a marriage solemnized in apparent compliance with law or attempted to enter into a civil union in apparent compliance with law, although the attempted marriage or civil union is or could be declared invalid, and: (I) If the attempted marriage or civil union could be declared invalid only by a court, the child is born during the attempted marriage or civil union or within three hundred days after its termination by death, annulment, declaration of invalidity of marriage or civil union, dissolution of marriage or civil union, or divorce; or (II) If the attempted marriage or civil union is invalid without a court order, the child is born within three hundred days after the termination of cohabitation; (c) After the child's birth, the person and the parent who gave birth to the child have married or entered into a civil union, or attempted to marry each other by a marriage solemnized in apparent compliance with law or enter into a civil union in apparent compliance with law, although the attempted marriage or civil union is or could be declared invalid, and: (I) The person has asserted parentage of the child in writing filed with the court or registrar of vital statistics, if such acknowledgment has not previously become a legal finding pursuant to subsection (2)(a.5) of this section; (II) With the person's consent, the person is named as the child's parent on the child's birth certificate; or (III) The person is obligated to support the child under a written voluntary promise or by court order or by an administrative order issued pursuant to section 26-13.5-110; (d) While the child is under the age of majority, the person receives the child into the person's home and openly holds out the child as the person's natural child; (e) (Deleted by amendment, L. 2022.) (f) The genetic tests or other tests of inherited characteristics have been administered pursuant to section 13-25-126, and the results show that the alleged genetic parent is not excluded as the probable genetic parent and that the probability of the person's genetic parentage is ninety-seven percent or higher. This subsection (1)(f) does not apply to a donor as defined in section 19-1-103. (2) (a) A presumption of parentage pursuant to subsection (1) of this section may be rebutted in an appropriate action only by clear and convincing evidence. If two or more conflicting presumptions arise, the presumption that, on the facts, is founded on the weightier considerations of policy and logic controls. The presumption is rebutted by a court decree establishing parentage of the child by another person other than the parent who gave birth. In determining which of two or more conflicting presumptions controls, based upon the weightier considerations of policy and logic, the judge or magistrate shall consider all pertinent factors, including but not limited to the following: (I) The length of time between the proceeding to determine parentage and the time that the presumed parent was placed on notice that the presumed parent might not be the genetic parent, unless the child was conceived through an assisted reproductive procedure; (II) The length of time during which the presumed parent has assumed the role of the child's parent; (III) The facts surrounding the presumed parent's discovery of the possibility that the presumed parent was not a genetic parent, unless the child was conceived through an assisted reproductive procedure; (IV) The nature of the existing parent-child relationship; (V) The child's age; (VI) The child's relationship to any presumed parent or parents; (VII) The extent to which the passage of time reduces the chances of establishing another person's parentage and a child support obligation in favor of the child; and (VIII) Any other factors that may affect the equities arising from the disruption of the parent-child relationship between the child and the presumed parent or parents or the chance of other harm to the child. (a.5) (I) A person and the parent who gave birth to the child may sign a voluntary acknowledgment of parentage to establish the parentage of the child. A voluntary acknowledgment of parentage may be signed by a parent who gave birth to the child and either: (A) Another person who is or believes themselves to be a genetic parent; or (B) Another person who is an intended parent of a child conceived through an assisted reproductive procedure. (II) A married person or person in a civil union who gives birth to a child may only sign a voluntary acknowledgment of parentage with a person who is not the married person's spouse or civil union partner if the spouse or civil union partner signs a denial of parentage. (b) A duly executed voluntary acknowledgment of parentage takes effect upon the filing of the document with the state registrar of vital statistics and may be rescinded within the earlier of: (I) Sixty days after execution of such acknowledgment; or (II) On the date of any administrative or judicial proceeding pursuant to this article or any administrative or judicial proceeding concerning the support of a child to which the signatory is a party. (c) An acknowledgment of parentage may be challenged in court only on the basis of fraud, duress, or mistake of material fact, with the burden of proof upon the challenger. Any legal responsibilities resulting from signing an acknowledgment of parentage, including child support obligations, continue during any challenge to the finding of parentage, except for good cause shown. (d) Except as otherwise provided in subsections (2)(b) and (2)(c) of this section, a voluntary acknowledgment of parentage that complies with this section and section 25-2-112, and is filed with the state registrar of vital statistics, is equivalent to an adjudication of parentage of the child and confers on the acknowledged parent all rights and duties of a parent. The court shall give full faith and credit to a voluntary acknowledgment of parentage that is effective in another state, including a federally recognized Indian tribe, if the acknowledgment was in a signed record and otherwise complies with the laws of the other state or federally recognized Indian tribe.

Source: L. 87: Entire title R&RE, p. 793, § 1, effective October 1. L. 89: (1)(c)(III) amended, p. 1247, § 3, effective April 1. L. 91: (1)(f) amended, p. 253, § 10, effective July 1. L. 97: (1)(c)(I), (1)(e), and (2) amended, p. 1274, § 13, effective July 1. L. 2003: (2)(a) amended, p. 1268, § 59, effective July 1. L. 2008: (2)(c) amended, p. 1656, § 2, effective August 15. L. 2022: Entire section amended, (HB 22-1153), ch. 210, p. 1389, § 4, effective August 10. L. 2023: IP(2)(b) amended, (SB 23-173), ch. 330, p. 1982, § 22, effective June 2. L. 2024: (1)(f) amended, (HB 24-1450), ch. 490, p. 3412, § 28, effective August 7.

Editor's note: This section was contained in a title that was repealed and reenacted in 1987. Provisions of this section, as it existed in 1987, are similar to those contained in § 19-6- 105 as said section existed in 1986, the year prior to the repeal and reenactment of this title.

Cross references: For the legislative declaration contained in the 1997 act amending subsections (1)(c)(I), (1)(e), and (2), see section 1 of chapter 236, Session Laws of Colorado 1997.

19-4-105.5. Commencement of proceedings - summons - automatic temporary injunction - enforcement. (1) All proceedings under this article shall be commenced in the manner provided by the Colorado rules of civil procedure or as otherwise provided in this section or section 26-13.5-104, C.R.S. (2) Upon commencement of a proceeding under this article by one of the parties, the other parties shall be served in the manner set forth in section 19-4-109 (2), the Colorado rules of civil procedure, or as otherwise provided in section 26-13.5-104, C.R.S. (2.5) Upon the commencement of a proceeding under this article, each party shall provide to the court, in the manner prescribed by the court, his or her social security number and the social security number of each child who is the subject of the proceeding under this article. (3) Proceedings under this article may be commenced prior to the birth of a child. (4) If a petition is filed by an alleged father or possible father pursuant to the requirements of section 19-5-103.7, the licensed child placement agency involved shall receive notice of the action in the same manner as a party to the action. (5) A summons issued upon commencement of a proceeding under this article shall contain the following advisements and notice: (a) That a request for genetic tests shall not prejudice the requesting party in matters concerning allocation of parental responsibilities pursuant to section 14-10-124 (1.5), C.R.S.; (b) That, if genetic tests are not obtained prior to a legal establishment of paternity and submitted into evidence prior to the entry of the final order establishing paternity, the genetic tests may not be allowed into evidence at a later date; and (c) (I) That, except in proceedings initiated pursuant to section 14-10-124.4 or in proceedings initiated by a delegate child support enforcement unit, as defined in section 26-13- 102.5 (1), pursuant to article 13 or 13.5 of title 26, or article 5 of title 14, upon personal service of the petition and summons on a respondent or upon waiver and acceptance of service by a respondent, a temporary injunction shall be in effect against both parties: (A) Enjoining each party from molesting or disturbing the peace of the other party; (B) Restraining each party from removing a minor child who is the subject of a proceeding under this article from the state without the consent of all other parties or an order of the court modifying the injunction; and (C) Restraining each party, without at least fourteen days' advance notification and the written consent of all other parties or an order of the court modifying the injunction, from canceling, modifying, terminating, or allowing to lapse for nonpayment of premiums, a policy of health insurance or life insurance that provides coverage to a minor child who is the subject of the proceeding or that names the minor child as a beneficiary of a policy. (II) The temporary injunction shall be in effect upon personal service of the petition and summons on a respondent or upon waiver and acceptance of service by a respondent and shall remain in effect for one hundred twenty days after its effective date unless all parties consent to a modification of the temporary injunction. The court may, upon the motion of a party or upon its own motion, modify the length of time the temporary injunction is in effect to a shorter or longer period of time as the court deems appropriate. (6) The provisions of the temporary injunction described in subsection (5) of this section shall be printed on the summons and the petition. A party may apply to the court for further temporary orders, an expanded temporary injunction, or modification or revocation of the temporary injunction. (7) For purposes of enforcing the automatic temporary injunction described in paragraph (c) of subsection (5) of this section, if a respondent shows a duly authorized peace officer, as described in section 16-2.5-101, C.R.S., a copy of the petition and summons filed and issued pursuant to this section, or if a petitioner shows the peace officer a copy of the petition and summons filed and issued pursuant to this section together with a certified copy of the affidavit of service of process or a certified copy of the waiver and acceptance of service, and the peace officer has cause to believe that a violation of the part of the automatic temporary injunction that enjoins a party from molesting or disturbing the peace of the other party has occurred, the peace officer shall use every reasonable means to enforce that part of the injunction against the petitioner or respondent, as applicable. A peace officer shall not be held civilly or criminally liable for his or her actions pursuant to this subsection (7) if the peace officer acts in good faith and without malice.

Source: L. 94: Entire section added, p. 1541, § 13, effective May 31. L. 96: Entire section amended, p. 612, § 13, effective July 1. L. 2005: (3) and (4) added, p. 102, § 3, effective July 1; (5) added, p. 378, § 3, effective January 1, 2006. L. 2006: (5)(b) amended, p. 516, § 2, effective August 7. L. 2010: (5) amended and (6) and (7) added, (HB 10-1097), ch. 39, p. 158, § 1, effective August 15. L. 2011: (2.5) added, (SB 11-123), ch. 46, p. 119, § 5, effective August 10. L. 2023: IP(5)(c)(I) amended, (HB 23-1026), ch. 243, p. 1307, § 7, effective August 7.

Cross references: For the short title ("Grandparents' Rights for Aaliyah and Myah Act") in HB 23-1026, see section 1 of chapter 243, Session Laws of Colorado 2023.