- 397 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

Tyler F., appellant, v. Sara P., appellee.

Geoffrey V., as next friend of J.F., a minor child, 

appellee and cross-appellant, v. Sara P., appellee 

and cross-appellee, and Tyler F., appellant 

and cross-appellee.

___ N.W.2d ___

Filed July 10, 2020. Nos. S-19-513, S-19-514.

1. Paternity: Appeal and Error. In a filiation proceeding, questions concerning child custody determinations are reviewed on appeal de novo on 

the record to determine whether there has been an abuse of discretion 

by the trial court, whose judgment will be upheld in the absence of an 

abuse of discretion.

2. Statutes. Statutory interpretation presents a question of law.

3. Judgments: Appeal and Error. When reviewing questions of law, an 

appellate court has an obligation to resolve the questions independently 

of the conclusion reached by the trial court.

4. Appeal and Error: Words and Phrases. Plain error exists where there 

is an error, plainly evident from the record, which prejudicially affects 

a substantial right of a litigant and is of such a nature that to leave it 

uncorrected would cause a miscarriage of justice or result in damage to 

the integrity, reputation, and fairness of the judicial process.

5. Appeal and Error. An appellate court may, at its option, notice plain 

error.

6. Paternity: Acknowledgments: Rescission: Time. In Nebraska, a paternity acknowledgment operates as a legal finding of paternity after the 

rescission period has expired.

7. Paternity: Acknowledgments. Paternity may be established by a 

properly executed acknowledgment, and establishment of paternity by 

acknowledgment is the equivalent of establishment of paternity by judicial proceeding.

8. Parental Rights: Child Custody: Paternity: Acknowledgments: DNA 

Testing. A father whose paternity is established by a final, voluntary 

Nebraska Supreme Court Online Library

www.nebraska.gov/apps-courts-epub/

07/17/2020 01:07 AM CDT
- 398 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

acknowledgment has the same right to seek custody as the child’s 

biological mother, even if genetic testing shows he is not the biological father.

9. Paternity: Acknowledgments: DNA Testing. DNA testing which later 

shows the identified individual is not the child’s biological father 

is insufficient to set aside a properly executed acknowledgment of 

paternity.

10. Paternity: Acknowledgments: Parent and Child. An acknowledgment 

legally establishes paternity and grants the individual named as father 

the legal status of a parent to the child regardless of genetic factors.

11. Paternity: Statutes. Paternity proceedings are purely statutory, and 

because the statutes regarding paternity proceedings modify the common 

law, they must be strictly construed.

12. Statutes: Appeal and Error. Statutory language is to be given its plain 

and ordinary meaning, and an appellate court will not resort to interpretation to ascertain the meaning of statutory words which are plain, 

direct, and unambiguous.

13. Statutes: Legislature: Intent. Components of a series or collection of 

statutes pertaining to a certain subject matter are in pari materia and 

should be conjunctively considered and construed to determine the 

intent of the Legislature, so that different provisions are consistent, harmonious, and sensible.

14. Paternity: Parties: Acknowledgments. A previous paternity determination, including a properly executed and undisturbed acknowledgment, 

must be set aside before a third party’s paternity may be considered.

15. Paternity. A party seeking to establish paternity must first set aside an 

existing determination.

16. Acknowledgments: Proof. In order to set aside an unrevoked acknowledgment, the moving party has the burden to show the acknowledgement was a result of fraud, duress, or material mistake.

17. Paternity: Acknowledgments. A party executing an acknowledgment 

of paternity has a duty to exercise reasonable diligence in the execution 

of the acknowledgment to ensure that it was grounded in fact.

18. Words and Phrases. Reasonable diligence means appropriate action 

where there is some reason to awaken inquiry and direct diligence in a 

channel in which it will be successful.

Appeals from the District Court for Lancaster County: Kevin 

R. McManaman, Judge. Affirmed in part, and in part reversed 

and remanded for further proceedings.

Andrea L. McChesney, of McChesney Family Law Office, 

for appellant.
- 399 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

Joel Bacon and Tara L. Gardner, of Keating, O’Gara, Nedved 

& Peter, P.C., L.L.O., for appellee Geoffrey V.

Heavican, C.J., Miller-Lerman, Cassel, Stacy, Funke, 

Papik, and Freudenberg, JJ.

Funke, J.

The district court awarded joint legal and physical custody 

of J.F. to Sara P., Tyler F., and Geoffrey V. Tyler appealed 

and assigned various errors. Geoffrey then cross-appealed. We 

conclude that the district court did not err in finding that Sara 

failed to meet her burden to set aside the notarized acknowledgment of paternity executed by Tyler and Sara at the time of 

J.F.’s birth. We further conclude that the trial court committed 

plain error in considering Geoffrey’s paternity complaint while 

failing to give proper legal effect to Tyler’s acknowledgment 

of paternity. We therefore affirm the court’s denial of Sara’s 

counterclaim to set aside Tyler’s acknowledgment of paternity; 

reverse the district court’s award of joint legal and physical 

custody of J.F. to Sara, Tyler, and Geoffrey; and remand the 

cause for further proceedings.

BACKGROUND

Sometime around November 2007, Tyler and Sara were dating and engaged in sexual intercourse. Sara gave birth to J.F. 

in August 2008. Sara continually represented to Tyler that he 

was the father of J.F., and Tyler signed an acknowledgment 

of paternity at the hospital when J.F. was born and is listed as 

J.F.’s father on the birth certificate.

Sara also engaged in sexual intercourse with Geoffrey 

around November 2007. Sara contends she believed Tyler 

was J.F.’s father because of information she received from 

her physician about her due date. At one point during the 

pregnancy, however, she contacted Geoffrey about the possibility that he might be the father and, about 8 to 9 months 

after J.F.’s birth, Geoffrey and Sara had discussions about 

genetic testing to determine paternity. Sara testified that she 
- 400 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

always had a “gut feeling” that J.F. might not be Tyler’s biological child and that this “gut feeling” that “maybe he could 

be [Geoffrey’s existed] when [Sara] was pregnant, when [J.F.] 

was born [and] when [J.F.] started really looking like him.” 

It is undisputed she did not tell Tyler about Geoffrey’s possible paternity.

Following J.F.’s birth, Tyler and Sara shared parenting 

responsibilities despite ceasing their romantic relationship, 

even through Sara’s move to Oklahoma in 2013. At the time 

of Sara’s move, J.F. was in the middle of his first year of 

preschool and the parties agreed J.F. would continue to attend 

school in Nebraska and reside with Tyler. After the school year, 

in the summer of 2014, Sara indicated to Tyler that she wanted 

J.F. to stay with her and attend kindergarten in Oklahoma.

Extending from the parties’ disagreement concerning J.F.’s 

schooling, Tyler filed a complaint to establish paternity, custody, and parenting time under case No. CI 14-2745, currently 

under appeal as case No. S-19-513. In his complaint, Tyler 

sought joint legal and physical custody of J.F., as well as an 

order determining paternity. Tyler alleged in this complaint that 

he “believes he is the biological father of [J.F.] and has always 

held himself out as such,” that Sara “has always held [Tyler] 

out as [J.F.’s] biological father,” and that Tyler “is listed and 

acknowledged on [J.F.’s] birth certificate.”

In Sara’s answer and counterclaim, she alleged that Tyler 

is not J.F.’s biological father and that he has no standing to 

request custody of J.F. As such, Sara sought, in part, that the 

district court dismiss Tyler’s complaint, declare Tyler not to be 

the biological father of J.F., and award Sara sole physical and 

legal custody.

During the proceedings, the court ordered DNA testing that 

showed Tyler was not J.F.’s biological father. Following receipt 

of the testing results, Sara amended her answer and counterclaim, seeking, among other things, an order rescinding Tyler’s 

acknowledgment of paternity on the ground of mutual mistake 

and disestablishing paternity.
- 401 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

Shortly after the DNA test excluded Tyler as the biological 

father, Sara reached out to Geoffrey and told him she believed 

he was the father. Geoffrey then filed a motion to intervene in 

Tyler’s case, seeking intervention as the “biological father of 

[J.F.]” However, the court denied Geoffrey’s motion because 

Geoffrey provided no basis to avoid the 4-year statute of 

limitations under Neb. Rev. Stat. § 43-1411 (Reissue 2016) and 

did not allege he was unaware of J.F.’s birth or the possibility 

of paternity.

Thereafter, Geoffrey filed a complaint to establish paternity under case No. CI 15-119, currently under appeal as case 

No. S-19-514, seeking that physical and legal custody be placed 

with Sara subject to his and Tyler’s visitation rights. Geoffrey’s 

complaint acknowledged Tyler as J.F.’s legal father, referencing Tyler’s acknowledgment of paternity, and explained that 

Geoffrey was not made aware he was J.F.’s biological father 

until October 2014, when Sara told him about the results of 

Tyler’s DNA test. The complaint’s caption listed “Geoffrey [V.], 

as next friend of [J.F.], a minor child,” as plaintiff. However, 

the text of the complaint and the signature line at the end of 

the complaint described only Geoffrey, individually, without 

mentioning his status as next friend of J.F. Geoffrey also noted 

that genetic testing established Tyler was not the biological father and alleged that Tyler’s belief he was the biological 

father was “based on the material mistake of fact based on the 

representations of Sara . . . at the time [J.F.] was conceived 

and born.” Geoffrey claimed, “The presumption that . . . Tyler 

. . . is the father of [J.F.], through his signed Acknowledgment 

of Paternity, has been rebutted through genetic testing and the 

records of the Nebraska Department of Health and Human 

Services should be corrected.”

Tyler filed an answer to Geoffrey’s complaint. In his answer, 

Tyler requested the court dismiss the complaint insofar “as 

the matter has already been decided in Case No. CI14-2745.” 

The answer did not specifically raise any statute of limitations defenses.
- 402 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

The court consolidated cases Nos. CI 14-2745 and CI 15-119, 

held a trial, and entered an order in January 2016. The court 

determined that Geoffrey had standing to act in the capacity 

of next friend of J.F., that Tyler is the father of J.F. by reason 

of the acknowledgment of paternity, and that Geoffrey is the 

father of J.F. by reason of biological testing. The court found 

Sara failed to meet her burden to establish mutual mistake 

and denied her motion to set aside Tyler’s acknowledgment. 

The court, therefore, considered the rights and interests of 

Tyler, Geoffrey, and Sara in making custody, parenting time, 

and child support determinations. The court awarded legal 

and physical custody of J.F. to Tyler, subject to visitation with 

Geoffrey and Sara, until December 31, 2016, at which time all 

three parties were awarded joint legal and physical custody. 

The court also calculated child support by considering the 

incomes of Tyler, Geoffrey, and Sara and ordered Geoffrey and 

Sara to pay child support until December 31, when all support 

obligations were to cease.

Tyler appealed, assigning the district court erred in finding 

that Geoffrey had standing to bring his claim as next friend of 

J.F. and in deviating from the child support guidelines in setting child support. Geoffrey cross-appealed and assigned that 

the court erred in concluding he had not raised a claim in his 

individual capacity and, to the extent the appellate court might 

conclude Tyler’s paternity acknowledgment had to be set aside 

before determining that Geoffrey had paternity, that the court 

erred in evaluating the material mistake of fact question from 

Sara’s perspective.

The Nebraska Court of Appeals reversed the district court’s 

order. 1 First, the Court of Appeals determined Geoffrey lacked 

standing to raise any claims on J.F.’s behalf, as J.F.’s next 

friend, because J.F. was in the custody of Sara, his biological mother, and Tyler, his legal father, and thus not without 

a guardian. However, the appellate court found that the trial 

1 Tyler F. v. Sara P., 24 Neb. App. 370, 888 N.W.2d 537 (2016).
- 403 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

court failed to address whether Geoffrey was also bringing 

his claims in his individual capacity. As such, the cause was 

remanded to the district court for determination of whether 

Geoffrey also brought his claims in his individual capacity 

and whether such individual claims are barred by the statute 

of limitations.

On remand, the district court found that Geoffrey had 

brought his claims in both his individual capacity and as J.F.’s 

next friend due to the language and intended beneficiary of 

the complaint. The court then found that Geoffrey’s individual 

claims were not barred by the statute of limitations, because 

Tyler waived the defense by failing to assert it in his answer 

or another responsive pleading. The court found that even if 

Tyler had not waived the statute of limitations, it was tolled 

because Geoffrey alleged he was not made aware he was J.F.’s 

biological father until October 2014 and Tyler’s answer did 

not sufficiently deny this allegation. Similarly, the court determined that res judicata did not bar Geoffrey’s claims due to the 

court’s denial of Geoffrey’s motion to intervene, because Tyler 

failed to raise it as an affirmative defense and because even if 

he had, res judicata was inapplicable to the instant case. Given 

the court’s finding that Geoffrey also brought his claims in 

his individual capacity, the court reinstated its previous order 

“with the caveat that the order applies to [Geoffrey] individually rather than as next friend of J.F.”

ASSIGNMENTS OF ERROR

Tyler assigns, restated, that the district court erred in (1) 

finding Geoffrey brought his claims in his individual capacity, (2) finding Tyler waived the statute of limitations defense, 

(3) finding the statute of limitations was tolled, (4) finding 

Geoffrey’s claims were not barred by the denial of his motion 

to intervene, (5) failing to find Geoffrey’s claims were timebarred, and (6) deviating from the child support guidelines in 

the custody award.

On cross-appeal, Geoffrey assigns, contingent on a finding of plain error in the district court’s conclusion that Tyler’s 
- 404 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

paternity acknowledgment did not have to be set aside before 

the district court could determine whether Geoffrey had paternity, that the court erred in failing to set aside Tyler’s paternity 

acknowledgment.

STANDARD OF REVIEW

[1] In a filiation proceeding, questions concerning child 

custody determinations are reviewed on appeal de novo on the 

record to determine whether there has been an abuse of discretion by the trial court, whose judgment will be upheld in the 

absence of an abuse of discretion. 2

[2,3] Statutory interpretation presents a question of law. 3

When reviewing questions of law, an appellate court has an 

obligation to resolve the questions independently of the conclusion reached by the trial court. 4

ANALYSIS

Acknowledgment of Paternity

Before reaching the assigned errors, we first address the 

question of whether the district court committed plain error 

in determining it unnecessary to set aside Tyler’s paternity 

acknowledgment before considering Geoffrey’s complaint to 

establish paternity.

[4,5] Plain error exists where there is an error, plainly evident from the record, which prejudicially affects a substantial 

right of a litigant and is of such a nature that to leave it uncorrected would cause a miscarriage of justice or result in damage 

to the integrity, reputation, and fairness of the judicial process. 5

An appellate court may, at its option, notice plain error. 6

2 State on behalf of Kaaden S. v. Jeffery T., 303 Neb. 933, 932 N.W.2d 692 

(2019).

3 Fetherkile v. Fetherkile, 299 Neb. 76, 907 N.W.2d 275 (2018).

4 Id.

5 See, In re Application No. OP-0003, 303 Neb. 872, 932 N.W.2d 653 

(2019); Osantowski v. Osantowski, 298 Neb. 339, 904 N.W.2d 251 (2017).

6 Mays v. Midnite Dreams, 300 Neb. 485, 915 N.W.2d 71 (2018).
- 405 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

When J.F. was born, Tyler and Sara signed a notarized 

acknowledgment of paternity in which they attested that Tyler 

was J.F.’s biological father. Although Sara’s amended answer 

and counterclaim sought to set aside this acknowledgment following the court-ordered DNA test that showed Tyler was not 

J.F.’s biological father, the district court declined to do so, finding Sara failed to meet her burden to prove a material mistake 

of fact had occurred. As such, the court found the acknowledgment remains in effect. However, the court went on to determine that it could consider Geoffrey’s simultaneous claim of 

paternity without setting aside Tyler’s acknowledgment. The 

court then found that both Tyler and Geoffrey were the fathers 

of J.F. and that Sara retained the position of mother under the 

paternity statutes.

[6] In Nebraska, a paternity acknowledgment operates 

as a legal finding of paternity after the rescission period 

has expired. 7 The proper legal effect of a signed, notarized 

acknowledgment of paternity is a finding that the individual 

who signed as the father is in fact the legal father. 8 Neb. Rev. 

Stat. § 43-1409 (Reissue 2016) establishes this legal effect 

and provides:

The signing of a notarized acknowledgment, whether 

under section 43-1408.01 or otherwise, by the alleged 

father shall create a rebuttable presumption of paternity as 

against the alleged father. The signed, notarized acknowledgment is subject to the right of any signatory to rescind 

the acknowledgment within the earlier of (1) sixty days 

or (2) the date of an administrative or judicial proceeding 

relating to the child, including a proceeding to establish a 

support order in which the signatory is a party. After the 

rescission period a signed, notarized acknowledgment is 

considered a legal finding . . . .

7 In re Adoption of Jaelyn B., 293 Neb. 917, 883 N.W.2d 22 (2016); Cesar 

C. v. Alicia L., 281 Neb. 979, 800 N.W.2d 249 (2011).

8 Cesar C., supra note 7.
- 406 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

[7] Relatedly, in describing child support obligations of the 

parents, Neb. Rev. Stat. § 43-1402 (Reissue 2016) refers to 

“[t]he father of a child whose paternity is established either by 

judicial proceedings or by acknowledgment as hereinafter provided . . . .” We have explained that this language in § 43-1402 

contemplates that paternity may be established by a properly 

executed acknowledgment and that establishment of paternity 

by acknowledgment is the equivalent of establishment of paternity by judicial proceeding. 9

[8] Reading §§ 43-1402 and 43-1409 together, the provision in § 43-1409 that an acknowledgment is a “legal finding” 

means that a properly executed acknowledgment legally establishes paternity in the person named in the acknowledgment as 

the father. 10 A father whose paternity is established by a final, 

voluntary acknowledgment has the same right to seek custody 

as the child’s biological mother, even if genetic testing shows 

he is not the biological father. 11

Here, it is undisputed that the acknowledgment of paternity 

signed by Tyler and Sara was properly executed. Additionally, 

there is no evidence that either party to the acknowledgment 

sought to rescind it within the statutory rescission period. The 

acknowledgment remained in full force and effect at the time 

of Tyler’s paternity action and legally determined Tyler’s paternity of J.F. As such, upon finding that the notarized acknowledgment of paternity had been properly signed, the court 

should have treated Tyler’s paternity as having been legally 

established and treated this action as one solely to determine 

issues of custody and support as between two legal parents, 

and not one to establish paternity. 12

[9,10] In her answer and counterclaim, Sara alleged Tyler 

was neither the legal nor the biological father of J.F. As a 

9 See id.

10 See id.

11 In re Adoption of Jaelynn B., supra note 7.

12 See Cesar C., supra note 7.
- 407 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

result, she sought DNA testing to confirm her allegations. 

However, the Legislature has established that a properly executed acknowledgment of paternity cannot be set aside merely 

by DNA testing which later shows the identified individual is 

not the child’s biological father. 13 While § 43-1412.01 provides 

that “[a]n individual may file a complaint for relief and the 

court may set aside a final judgment . . . or any other legal 

determination of paternity if a scientifically reliable genetic 

test . . . establishes the exclusion of the individual named as a 

father in the legal determination,” it further clarifies that “[a] 

court shall not grant relief from determination of paternity 

if the individual named as father . . . completed a notarized 

acknowledgment of paternity . . . .” We have found that this 

provision provides further support for the conclusion that an 

acknowledgment legally establishes paternity and grants the 

individual named as father the legal status of a parent to the 

child regardless of genetic factors. 14 Because Tyler’s acknowledgment remained in full force and effect and established his 

paternity of J.F. regardless of genetic factors, the trial court had 

no basis to order the DNA testing.

That is not to say an acknowledgment cannot be challenged 

and set aside, but the grounds for doing so are limited. Section 

43-1409 explains that a properly executed acknowledgment 

“may be challenged only on the basis of fraud, duress, or 

material mistake of fact with the burden of proof upon the 

challenger.” Therefore, under the statutory scheme, before Sara 

could challenge paternity and subject Tyler to genetic testing, she needed to overcome the acknowledgment establishing 

Tyler was J.F.’s legal father by showing fraud, duress, or material mistake. 15

Following the inappropriately ordered DNA test, Sara 

amended her answer and counterclaim to seek to set aside 

13 See, Neb. Rev. Stat. § 43-1412.01 (Reissue 2016); Cesar C., supra note 7.

14 In re Adoption of Jaelyn B., supra note 7.

15 See, id.; Cesar C., supra note 7.
- 408 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

the acknowledgment of paternity. Sara claimed both parties 

thereto had been under a material mistake of fact due to her 

being informed of an “erroneous due date by her treating physician.” Sara specifically alleged that her projected due date 

was August 11, 2008, from which she believed Tyler was the 

father based upon a 9-month gestation period, but that this 

due date was incorrect and that labor was induced several 

days earlier.

In its order declining to set aside the acknowledgment, 

the court correctly considered the issue without concern to 

the results of the DNA test. The court found that there was 

clear evidence Sara knew of the possibility Tyler was not the 

father during and following pregnancy and that even though 

Tyler was under the mistaken belief he was J.F.’s biological 

father, it was Sara’s burden as the challenger to show a material mistake on her part, which she did not. Because the court 

declined to set the acknowledgment aside, it remains in full 

force and effect.

Geoffrey’s Determination of Paternity

Geoffrey’s complaint to establish his paternity of J.F. alleges 

that Geoffrey did not know he was J.F.’s father until Sara 

informed him that DNA testing excluded Tyler as J.F.’s biological father. Regardless of whether that allegation is supported by the record, as noted above, the court had no basis to 

order this test, due to the application of the acknowledgment 

of paternity. 16

Further, Geoffrey’s complaint fails to move for Tyler’s 

acknowledgment of paternity to be set aside. Instead, Geoffrey 

argues, and the district court agreed, that a determination that 

Tyler has paternity of J.F. is of no consequence when determining whether Geoffrey has paternity of J.F. However, this 

proposition is at odds with Nebraska’s paternity and related 

statutes and the Nebraska Child Support Guidelines as currently constructed.

16 See id.
- 409 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

[11-13] We have recognized that paternity proceedings 

are purely statutory and that because the statutes regarding 

paternity proceedings modify the common law, they must be 

strictly construed. 17 Statutory language is to be given its plain 

and ordinary meaning, and an appellate court will not resort 

to interpretation to ascertain the meaning of statutory words 

which are plain, direct, and unambiguous. 18 Components of a 

series or collection of statutes pertaining to a certain subject 

matter are in pari materia and should be conjunctively considered and construed to determine the intent of the Legislature, 

so that different provisions are consistent, harmonious, 

and sensible. 19

Actions to determine paternity and parental support are governed by Neb. Rev. Stat. §§ 43-1401 through 43-1418 (Reissue 

2016 & Cum. Supp. 2018). Throughout these statutes, the 

Legislature has used language which recognizes the possibility of only a singular paternity determination. For example, 

§ 43-1402 describes “[t]he father of a child whose paternity is 

established,” “[t]he mother of a child,” and “each parent” in 

explaining support liability for a child. (Emphasis supplied.) 

Section 43-1403 describes possible county obligations of support “[i]n case of the neglect or inability of the parents, or 

either of them, to support a child . . . .” (Emphasis supplied.) 

Section 43-1404 designates the “liability of the father or 

mother of a child for its support” in explaining the discharge of 

support obligations. (Emphasis supplied.) Section 43-1405 uses 

the singular “the father” language several times in describing 

the discharge of support liability by settlement. (Emphasis 

supplied.) Section 43-1407 identifies “[t]he father of a child” 

in its explanation of liability for birth, pregnancy, and medical expenses. (Emphasis supplied.) Section 43-1410 explains, 

“Any judicially approved settlement or order of support made 

17 State on behalf of B.M. v. Brian F., 288 Neb. 106, 846 N.W.2d 257 (2014).

18 In re Application No. OP-0003, supra note 5.

19 Id.
- 410 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

by a court having jurisdiction in the premises shall be binding on the legal representatives of the father or mother in the 

event of his or her death . . . .” (Emphasis supplied.) Section 

43-1412(3), in explaining a court’s continued jurisdiction of a 

paternity action to order support and court costs, states:

If a judgment is entered under this section declaring the 

alleged father to be the father of the child, the court shall 

retain jurisdiction of the cause and enter such order of 

support, including the amount, if any, of any court costs 

and attorney’s fees which the court in its discretion deems 

appropriate to be paid by the father . . . .

(Emphasis supplied.)

Statutes under Nebraska’s Parenting Act 20 use similar limiting language. Section 43-2922(12) describes the existence 

of only two parents and defines “[j]oint physical custody” as 

“mutual authority and responsibility of the parents regarding 

the child’s place of residence and the exertion of continuous 

blocks of parenting time by both parents over the child for 

significant periods of time.” (Emphasis supplied.) This “both 

parents” language is used in other parts of the Parenting Act, 

including the following sections: § 43-2924(2), in describing 

the applicability of the Parenting Act for custody determinations; § 43-2929(4), in explaining that both parents continue 

to have parental rights regardless of a custody determination in a parenting plan unless the rights are terminated; and 

§ 43-2937(4), in describing when court-ordered mediation or 

alternative dispute resolution is required under the Parenting 

Act. Relatedly, § 43-2930(1) lists permissible information 

a child information affidavit may include when certain circumstances are present, including “criminal no-contact orders 

against either parent.” (Emphasis supplied.) The language of 

§ 43-2932 considers the existence of only two parents in the 

requirements under subsection (1)(a)(iv) that a court develop 

20 See Neb. Rev. Stat. §§ 43-2920 to 43-2943 (Reissue 2016, Cum. Supp. 

2018 & Supp. 2019).
- 411 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

a parenting plan if “a parent . . . has interfered persistently 

with the other parent’s access to the child;” under subsection 

(1)(b)(iv) of additional permissible limitations of a parenting 

plan, including “[r]estraints on the parent from communication with or proximity to the other parent or the child;” and 

under subsection (3) that the “parent found to have engaged in 

the behavior . . . has the burden of proving” the rights granted 

under the parenting plan “will not endanger the child or the 

other parent.” (Emphasis supplied.)

We are mindful that following the U.S. Supreme Court’s 

decision in Obergefell v. Hodges,

 21 our courts are now hearing cases involving two legal mothers or two legal fathers. 

But our current parentage statutes have not changed, and 

these statutes are still gender based, so the language of our 

opinion is necessarily gender based as well. In other words, 

Nebraska’s statutory scheme on parentage accommodates only 

two parents and primarily refers to one mother and one father. 

Here, the trial judge recognized three legal parents (one 

mother and two fathers), and that is simply not suppported by 

Nebraska law.

The Nebraska Child Support Guidelines also use language 

which assumes the existence of only a singular paternity determination, including the identifiers “both parents,” “either parent,” and “both parties.” 22 Though Nebraska’s judicial branch 

has revised its child support guidelines to be gender neutral, even the revised guidelines still accommodate just two 

legal parents.

[14] In considering the plain language of our paternity 

and related statutes, the Legislature’s use of the singular “the 

father” indicates an intention that there can only be one paternity designation at a time, and the use of “both parents,” 

21 Obergefell v. Hodges, ___ U.S. ___, 135 S. Ct. 2584, 192 L. Ed. 2d 609 

(2015).

22 See, e.g., Neb. Ct. R. § 4-201; Neb. Ct. R. §§ 4-203, 4-204, 4-206, and 

4-215 (rev. 2020); Neb. Ct. R. § 4-214 (rev. 2016).
- 412 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

“either parent,” “either party,” and “both parties” supports 

this reading. Accordingly, we hold that a previous paternity 

determination, including a properly executed and undisturbed 

acknowledgment, must be set aside before a third party’s paternity may be considered.

To find that one paternity determination has no effect on 

subsequent claims of paternity would render our decision in 

Cesar C. v. Alicia L. 23 inconsequential. In Cesar C., we determined that a mother’s request for DNA testing of the acknowledged father to determine whether he was actually the child’s 

biological father should have been denied by the trial court 

because the acknowledgment of paternity was undisturbed and 

properly executed. As such, there was already a determination 

of paternity of the child at issue and there could not be another 

action to determine paternity without first setting aside the 

acknowledgment. 24

[15] Our holding in Cesar C. applies to the instant case 

because just like the mother in Cesar C., Sara sought another 

paternity determination even though an acknowledgment 

remained applicable, the court failed to give adequate weight to 

the undisturbed acknowledgment and inappropriately ordered 

DNA testing for the purposes of establishing the child’s paternity, and the DNA test established the legal father was not the 

child’s biological father. Herein, Geoffrey then filed a complaint to establish his paternity based upon the DNA results 

communicated to him by Sara and did not seek to set aside 

the acknowledgment. If the paternity statutes allow for another 

party to establish simultaneous paternity without setting aside 

a properly executed acknowledgment of paternity, the DNA 

tests in Cesar C. and in this case would not be prohibited 

because they would provide a basis for a third party to seek 

such a simultaneous paternity ruling. However, in line with 

our opinion in Cesar C. and as analyzed above, the paternity 

23 Cesar C., supra note 7.

24 Id.
- 413 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

statutes require that a party seeking to establish paternity must 

first set aside an existing determination.

Other courts have come to this same conclusion. 25 In Barr 

v. Bartolo,

 26 the Pennsylvania Superior Court analyzed whether 

an undisturbed previous support order barred a subsequent 

determination of paternity in a third party. Under Pennsylvania 

law, the entry of a court order for support of a child necessarily 

determines the alleged father’s paternity. 27 As such, the support 

order judicially determined paternity in the husband and the 

court held that the previous determination barred relitigation of 

paternity without striking that first determination. 28

In Sinicropi v. Mazurek,

 29 the Michigan Court of Appeals 

considered what effect an unrevoked acknowledgment of paternity would have on an action to establish paternity. The trial 

evidence indicated that the biological father was seeking to 

establish his paternity of the minor child after the legal father 

had previously executed an unrevoked acknowledgment of 

paternity. 30 In granting the biological father’s complaint to 

establish paternity, the trial court effectively ruled that the child 

had two legal fathers. 31 On appeal, the appellate court reversed 

and held that an order of filiation cannot be entered if a proper 

acknowledgment of parentage was previously executed and 

has not been revoked. 32 The court further held that an unrevoked acknowledgment already legally established paternity 

and conferred the status of natural and legal father upon the 

man executing the acknowledgment, which in turn entitled him 

25 Barr v. Bartolo, 927 A.2d 635 (Pa. Super. 2007); Sinicropi v. Mazurek, 273 

Mich. App. 149, 729 N.W.2d 256 (2006).

26 Barr, supra note 25.

27 Id.

28 Id.

29 Sinicropi, supra note 25.

30 Id.

31 Id.

32 Id.
- 414 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

to seek custody or parenting time if desired and obligated him 

to pay support if appropriate. 33

In accordance with all of the above, the district court 

committed plain error in considering Geoffrey’s complaint to 

establish his paternity of J.F. when Tyler’s acknowledgment 

remained in place and established Tyler as J.F.’s father.

Geoffrey’s Cross-Appeal

In his cross-appeal, Geoffrey acknowledges the possibility that the district court committed plain error in finding his 

paternity without seeking to set aside Tyler’s acknowledgment 

of paternity. As such, Geoffrey assigns the district court erred 

in failing to set aside the acknowledgment. Geoffrey claims the 

court incorrectly limited its consideration of whether a material 

mistake of fact occurred to Sara’s perspective, instead of considering it from his perspective.

We note that Geoffrey did not independently move the court 

to set aside Tyler’s acknowledgment. Instead, his complaint 

to establish paternity merely referenced Sara’s allegation that 

Tyler’s belief that he was the biological father was based on a 

material mistake of fact. Specifically, Geoffrey alleged:

Genetic testing was completed establishing that 

Tyler . . . is not the father of [J.F.] [Tyler’s] belief that 

he was the father of [J.F.] was based on the representations of Sara . . . , and . . . said reliance was based on 

the material mistake of fact based on the representations 

of Sara . . . at the time [J.F.] was conceived and born. 

The presumption that . . . Tyler . . . is the father of [J.F.], 

through his signed Acknowledgment of Paternity, has 

been rebutted through genetic testing and the records of 

the Nebraska Department of Health and Human Services 

should be corrected.

As a result, we consider Sara’s prayer in her amended 

answer that the district court rescind Tyler’s acknowledgment 

33 Id.
- 415 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

of paternity. Specifically, in the “Affirmative Defenses” section 

of her amended answer, Sara alleges:

[J.F.] was born at the Bryan LGH Medical Center East in 

August of 2008. [Sara] was initially informed of an erroneous due date by her treating physician. The initial due 

date was projected to be on August 11, 2008. Based on 

the due date provided to [Sara], she mistakenly believed 

that Tyler . . . was the father of [J.F.] based on a 9 month 

gestation period. However, the anticipated due date was 

incorrect and labor was induced [several days earlier]. 

Accordingly, the parties hereto were under a material mistake of fact as [to] the biological father of [J.F.]

Additionally, under a section titled “Counterclaim: Custody,” 

Sara alleged: “The Acknowledgment of Paternity executed by 

[Tyler and Sara] herein was executed under a material mistake of fact precipitated by an inaccurate due date provided 

to [Sara]. To the extent the Acknowledgment of Paternity 

is rescinded the legal determination of paternity should be 

set aside.”

[16] As explained above, in order to set aside an unrevoked 

acknowledgment, the moving party has the burden to show 

the acknowledgment was a result of fraud, duress, or material 

mistake. 34 Sara, as the challenging party, had the duty to show 

that the acknowledgment resulted from a material mistake as 

she claimed. 35 In our review, we therefore evaluate the district 

court’s decision not to set aside the acknowledgment based 

upon Sara’s allegation that there was a material mistake of fact 

in the execution of the acknowledgment by Tyler and Sara as 

the executing parties, and not from Geoffrey’s perspective as a 

nonexecuting party.

In seeking to set aside Tyler’s paternity, Sara alleged only 

that she was under a material mistake of fact that Tyler was the 

biological father because her treating physician projected her 

34 § 43-1409.

35 See id.
- 416 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

due date to be on August 11, 2008, when J.F. was actually born 

several days earlier. Based upon this projected due date, Sara 

calculated a 9-month gestation period and allegedly believed 

Tyler was the biological father.

The record contradicts Sara’s allegation that she was under 

the mistaken belief as to J.F.’s biological father because she 

was told this incorrect due-date projection. If Sara received an 

incorrect projection of her due date, the due date was no longer 

at issue when J.F. was born, as Sara herself indicated when she 

testified Tyler should have known he was not the biological 

father due to J.F.’s date of birth.

The record also demonstrates that Sara knew of the possibility Geoffrey was the biological father during her pregnancy. 

Sara contacted Geoffrey about this possibility during the pregnancy and again 8 to 9 months after J.F.’s birth. Sara testified 

that she always believed that Geoffrey, instead of Tyler, might 

be J.F.’s biological father. Geoffrey and Sara talked soon after 

J.F. was born about performing genetic testing to determine 

whether Geoffrey was the father, but neither took any further action.

[17,18] It is clear that Sara knew Geoffrey could be J.F.’s 

biological father, even after being told the projected due date, 

and she communicated such possibility to Geoffrey. Due to 

this known possibility, Sara had a duty to exercise reasonable diligence in the execution of the acknowledgment of 

Tyler’s paternity to ensure that it was grounded in fact. 36 We 

have explained that reasonable diligence “‘means appropriate action where there is some reason to awaken inquiry and 

direct diligence in a channel in which it will be successful.’” 37

However, there is no evidence in the record that Sara exercised such reasonable diligence beyond her communications 

36 See Alisha C. v. Jeremy C., 283 Neb. 340, 808 N.W.2d 875 (2012).

37 Id. at 346, 808 N.W.2d at 881. See, also, DeVaux v. DeVaux, 245 Neb. 611, 

514 N.W.2d 640 (1994) (superseded by statute on other grounds as stated 

in Alisha C., supra note 36).
- 417 -

Nebraska Supreme Court Advance Sheets

306 Nebraska Reports

TYLER F. v. SARA P.

Cite as 306 Neb. 397

with Geoffrey. As such, the district court did not err in finding 

Sara failed to meet her burden and denying her motion to set 

aside Tyler’s acknowledgment.

Considering all of the above, the district court’s finding 

that Sara, and Geoffrey in support of Sara’s motion, failed to 

show the alleged material mistake of fact is supported by the 

record. Accordingly, the district court’s denial of Sara’s motion 

to set aside Tyler’s acknowledgment of his paternity of J.F. 

is affirmed.

CONCLUSION

The district court did not err in finding that Sara failed to 

meet her burden to set aside the notarized acknowledgment 

of paternity executed by Tyler and Sara at the time of J.F.’s 

birth. Additionally, a previous paternity determination, including a properly executed and undisturbed acknowledgment of 

paternity, must be set aside before a third party’s paternity may 

be considered. As a result, the district court committed plain 

error considering Geoffrey’s paternity complaint while failing to give proper legal effect to Tyler’s acknowledgment of 

paternity. Accordingly, we affirm the court’s denial of Sara’s 

counterclaim to set aside Tyler’s acknowledgment of paternity; 

reverse the district court’s award of joint legal and physical 

custody of J.F. to Sara, Tyler, and Geoffrey; and remand the 

cause for further proceedings.

Affirmed in part, and in part reversed and 

remanded for further proceedings.