Early Intervention to IEP in Washington: The Part C to Part B Transition

If your child has been receiving early intervention services through Washington's Birth to Three program, you are approaching one of the most consequential and time-sensitive transitions in special education: the move from Part C (early intervention) to Part B (school-based special education) at age 3. What happens in the months before your child's third birthday determines whether services continue without interruption — or whether your child falls through a gap that can take months to close.

Part C vs. Part B: The Critical Difference

Early intervention in Washington is provided through the Infant Toddler Early Intervention Program (ITEIP), which operates under Part C of IDEA. Part C serves children from birth to age 3 with developmental delays or disabilities, providing services like speech therapy, occupational therapy, physical therapy, and developmental intervention typically delivered in the home or community settings.

When your child turns 3, Part C ends. The responsibility for services shifts to the public school district under Part B of IDEA. Part B services are delivered through an Individualized Education Program (IEP), not the Individualized Family Service Plan (IFSP) you have been working with through Birth to Three. The shift is not automatic — it requires an evaluation, an eligibility determination, and a new IEP developed by the school district.

The Transition Timeline You Need to Know

Washington follows a specific timeline designed to ensure children do not lose services at the transition. The process must begin well before your child's third birthday:

At least 90 days before your child's third birthday: Your ITEIP service coordinator is required to initiate the transition planning process. This includes holding a transition conference that you participate in, at which the team discusses the child's future needs and the school district's role.

The transition conference: This meeting should include your ITEIP service coordinator and may include a representative from the school district. The purpose is to develop a transition plan outlining what steps will be taken to prepare your child for Part B services.

Referral to the school district: A formal referral is made to your school district. Once the district receives the referral, the standard evaluation timelines under WAC 392-172A-03005 apply: the district has 25 school days to decide whether to evaluate, and if it agrees to evaluate, 35 school days from receipt of your consent to complete the evaluation and hold an eligibility meeting.

By the third birthday: If your child is found eligible for Part B services, the IEP must be in place and services must begin no later than the child's third birthday — not weeks after, not when the district schedules a convenient meeting, but by the birthday itself.

What Happens When the Timeline Slips

Transition delays are one of the most common failures in Washington's special education system. Districts are sometimes slow to schedule evaluations, eligibility meetings get pushed out, or families are told that services will begin "in the fall" when the child's birthday falls in late spring or summer. None of that is acceptable under the law.

If your child turns 3 and an IEP has not been developed, that is a FAPE violation. If an IEP exists but services have not started, that is an implementation failure. If the evaluation was not completed within the required timelines, that is a procedural safeguard violation.

Document the referral date, the date you gave consent for evaluation, and every communication with the district about scheduling. If timelines are slipping, write to the special education director citing WAC 392-172A-03005 and the transition timelines, and request a written explanation and a specific date by which the evaluation and eligibility meeting will occur.

Eligibility Under Part B Is Not Automatic

A critical thing many parents do not realize: receiving Part C early intervention services does not automatically mean your child will qualify for Part B special education. Part C eligibility is based on developmental delay, and the thresholds are generally lower than those for Part B. Part B requires that the child have a disability under one of IDEA's thirteen eligibility categories and that the disability adversely affect educational performance.

Some children who received extensive early intervention services are found ineligible at the Part B transition — not because their needs have disappeared, but because the evaluation did not find sufficient deficit in the right categories.

If your child is found ineligible for Part B services and you believe the evaluation missed significant areas of need, you have the right to request an Independent Educational Evaluation at public expense under WAC 392-172A-05005. You also have the right to dispute the eligibility determination through OSPI mediation or due process.

What the IEP Should Look Like Coming Out of Early Intervention

The first IEP developed at the transition should reflect everything the evaluation found — not a reduced version of the IFSP, and not a minimal baseline because the district is not sure how the child will perform in a school setting.

A well-developed transition IEP includes:

• Present levels of performance based on the comprehensive evaluation, including areas evaluated under Part C
• Goals that pick up where early intervention left off — not starting from scratch
• Related services consistent with the evaluation's findings (speech, OT, PT as warranted)
• Placement in a setting that meets LRE requirements for a preschool-age child

Preschool special education settings are different from school-age settings. The LRE for a 3-year-old includes options like inclusion in community preschools with supports, district-operated inclusive preschool programs, or structured special education preschool settings for children with more intensive needs.

Getting Support Through the Transition

PAVE (Partnerships for Action, Voices for Empowerment) has specific resources for families navigating the Birth to Three to school-age transition, including guides on what to expect and how to participate effectively in the transition conference. They can be reached at wapave.org.

The Washington IEP & 504 Advocacy Playbook at /us/washington/advocacy/ includes the evaluation request letter and the framework for documenting timeline violations if the district misses the evaluation or IEP deadlines during the transition window. The transition from early intervention to school-age services is the first big test of whether your district will deliver what your child is owed — make sure you are ready for it.

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