H.J.B. v. A - J.A.B. Judgment Affirmed JUSTICE BERKENKOTTER delivered the Opinion of the Court, in which CHIEF JUSTICE BOATRIGHT JUSTICE MÁRQUEZ JUSTICE HOOD JUSTICE GABRIEL JUSTICE HART, 2023 CO 48

Background

A-J.A.B. was born testing positive for methamphetamine; Adams County Human Services filed a dependency-and-neglect petition and later moved to terminate the mother’s parental rights.
Mother twice asserted possible Cherokee and Lakota (Sioux) ancestry via a maternal great-grandmother but acknowledged she and the child were not enrolled and she likely would not qualify for tribal membership.
The juvenile court ordered mother to complete ICWA paperwork but did not initially direct the Department to perform due diligence under Colo. Rev. Stat. § 19-1-126(3); mother never completed the forms.
On appeal the court of appeals (A-J.A.B. I) held the juvenile court erred by not directing the Department to exercise due diligence and articulated a three-part due-diligence test; the case was remanded for limited further inquiry.
On remand the Department attempted to contact mother and successfully reached the maternal grandmother, who signed a declaration denying Native heritage; the juvenile court found the Department satisfied due diligence and that ICWA did not apply, and the court of appeals affirmed.
The Colorado Supreme Court granted certiorari to define the statutory meaning of “due diligence” in § 19-1-126(3), adopt a flexible but earnest-investigation standard, and affirm the court of appeals’ ultimate conclusion that the Department satisfied due diligence here.

Issues

Issue	Plaintiff's Argument (Mother)	Defendant's Argument (People/Department)	Held
What constitutes “due diligence” under § 19-1-126(3)?	Due diligence requires contacting the relevant tribes in every case where a child may be Indian so tribes can determine membership/eligibility.	Due diligence requires earnest efforts tailored to the facts; it need not always include contacting tribes or follow a rigid checklist.	Court adopts a flexible standard: earnestly investigate the basis for the heritage claim, contact specifically identified persons with knowledge, and seek any additional information that could show a reason to know.
Do generalized assertions of Indian heritage trigger ICWA notice?	Mother: Her statements of Cherokee and Lakota ancestry were sufficient to require tribal notice.	Department: Vague or generalized heritage claims without more do not meet the "reason to know" threshold and do not automatically trigger formal ICWA notice.	Court: Mere assertions of heritage, even naming tribes, do not by themselves create a "reason to know"; they instead trigger the § 19-1-126(3) due-diligence inquiry.
Did the Department satisfy § 19-1-126(3) in this case?	Mother: Department failed to contact the great-aunt specifically identified as the best source and failed to contact tribes.	Department: It attempted to contact mother repeatedly and obtained a signed declaration from maternal grandmother denying Native heritage; no other leads existed.	Court: Under the flexible standard, the Department’s post-remand efforts sufficed; juvenile court’s credibility findings were permissible, and ICWA did not apply.

Key Cases Cited

Haaland v. Brackeen, 143 S. Ct. 1609 (2023) (discussing ICWA’s substantive and procedural guardrails)
Adoptive Couple v. Baby Girl, 570 U.S. 637 (2013) (context on ICWA’s purpose to prevent wholesale removal of Indian children)
Miss. Band of Choctaw Indians v. Holyfield, 490 U.S. 30 (1989) (ICWA and tribal interests in child-custody matters)
Montana v. Blackfeet Tribe of Indians, 471 U.S. 759 (1985) (principle that statutes concerning Indian law are construed in favor of tribes)
People in Interest of E.A.M. v. D.R.M., 516 P.3d 924 (Colo. 2022) (holding that mere assertions of heritage without more do not create reason to know and trigger § 19-1-126(3))
People in Interest of My. K.M. v. V.K.L., 512 P.3d 132 (Colo. 2022) (background on ICWA’s legislative purpose and Colorado’s implementation)
People in Interest of K.C. v. K.C., 487 P.3d 263 (Colo. 2021) (on a court’s inquiry duties under Colorado’s ICWA statute)
People in Interest of A-J.A.B., 511 P.3d 750 (Colo. App. 2022) (division’s three-part due-diligence test and limited remand)
People in Interest of Jay.J.L., 514 P.3d 312 (Colo. App. 2022) (alternative approach stressing flexible, non-formulaic due diligence)