Short answer: Federal rules now bar CHIP waiting periods for children who leave group coverage, but some Texas HHSC handbook pages still describe the older 90-day wait, so confirm the actual CHIP start date with HHSC before dropping anyone.
Federal rule 42 CFR 457.805, as amended in 2024, says a state may not impose a waiting period before enrolling an eligible individual in CHIP after the individual is disenrolled from group health plan coverage, Medicaid or another insurance affordability program; states must instead monitor for substitution of coverage.
The Texas Works Handbook still contains a 90-day waiting period section, with a long list of good-cause exemptions (for example, involuntary loss of coverage, loss of Medicaid, the employer stopping dependent coverage, or a child’s premium costing more than 5% of household income). Until HHSC’s materials are fully updated, the safest practice is to get the start date in writing.
Either way, CHIP starts on a schedule (generally the first day of a later month, after enrollment and fee payment), so time the end of group coverage to avoid a gap.