IEP vs. IESP vs. RSA & P-3 Letters: NYC Special Ed Guide

What This Guide Covers

When a child is referred for special education services in NYC, parents encounter several acronyms: IEP, IESP, RSA, P-3, and P-4. Each term refers to a different document or mechanism. They are not interchangeable, although people often use them that way in casual conversation. This guide explains what each one is for and how they connect.

None of this is legal advice. It's a general orientation to how these instruments work in the NYC DOE system. For anything specific to your child, your CSE, CPSE, or a special education professional is the right resource.

IEP: Individualized Education Program

The IEP is the foundational document for a child who is enrolled in a NYC public school and has been found eligible for special education services through the Committee on Special Education (CSE) or, for children under five, the Committee on Preschool Special Education (CPSE). The IEP lays out the child's present levels of performance, annual goals, and the specific services, supports, and accommodations the school is required to provide: things like SETSS, related services, testing accommodations, or a specific class placement ratio (like 12:1:1).

Because the IEP applies to public school enrollment, the DOE itself is generally responsible for ensuring the services on the IEP are delivered, whether directly by DOE staff or by an approved provider working under DOE authorization.

IESP: Individualized Education Services Program

An IESP looks almost identical to an IEP in format (same present levels, same goals, same recommended services), but it's the document used when a child is enrolled in a nonpublic school (a private or parochial school) while the parent seeks special education services through the NYC DOE.

The key difference: because the child isn't enrolled in a DOE school, the DOE is not obligated to deliver services directly the way it would for a public school IEP. Instead, the IESP identifies what services the child is entitled to, and the family typically pursues those services through a Related Service Authorization (RSA) or, in some cases, direct funding mechanisms like P-3/P-4 letters. Both are explained below.

RSA: Related Service Authorization

An RSA is a voucher-like authorization letter issued by the DOE that allows a family (usually one whose child has an IESP, though RSAs can appear for public-school IEP situations as well when the DOE can't deliver a service directly) to obtain a specific related service (like occupational therapy, speech therapy, or counseling) from an independent, DOE-approved provider or agency, rather than from DOE staff.

The RSA specifies the service, frequency, and duration, similar to what would appear on the IEP or IESP, and the approved provider bills the DOE directly for delivering that service. For a family, the RSA is the document that connects a service listed on the IESP (for example, speech therapy twice a week) to an approved provider who can deliver it.

P-3 and P-4 Letters: Direct Funding for Nonpublic School Services

P-3 and P-4 letters are related but distinct mechanisms, generally associated with services and funding for students attending nonpublic schools. In broad terms, these letters function as the DOE's authorization for a specific type of service or funding arrangement tied to a nonpublic school student's IESP-recommended services, allowing the family or a provider to move forward with service delivery under DOE-authorized terms.

The specifics of P-3 vs. P-4 letter processes (including timing, renewal, and documentation requirements) can shift from year to year as DOE administrative procedures are updated. Because of that, confirm current requirements with your CSE liaison or an experienced provider rather than relying on last year's process.

How These Documents Connect

In simplified form:

1. Evaluation determines eligibility for special education services. 2. IEP (public school) or IESP (nonpublic school) documents what services the child needs. 3. RSA (and for nonpublic school students, sometimes P-3/P-4 letters) is the mechanism that authorizes an approved outside provider to deliver and get paid for those services when the DOE isn't delivering them directly.

Public school families most often deal with IEPs and, when services aren't available in-house, RSAs. Nonpublic school families most often deal with IESPs, RSAs, and potentially P-3/P-4 letters, depending on the specific service and DOE procedures in effect for that school year.

Common Points of Confusion

• "My child has an IEP, so why do we need an RSA?" Usually because a specific mandated service (say, occupational therapy) isn't available through DOE staff at your child's school, so the DOE authorizes an outside provider instead.
• "Is an IESP a lesser version of an IEP?" No. It reflects the same evaluation and goal-setting process; it exists because of where the child is enrolled, not because the child's needs are viewed differently.
• "Do RSAs expire?" Authorizations are generally tied to a school year and specific service parameters, so renewal each year (and sometimes mid-year, if the mandate changes) is normal and expected. Don't assume last year's authorization carries forward automatically.

What Families Should Keep Track Of

Because these documents govern who is responsible for delivering (and paying for) your child's services, keep organized copies of the current IEP or IESP, any RSA or P-3/P-4 letters, and correspondence with your CSE. If a service isn't starting on time or a provider says they're waiting on authorization, having these documents on hand makes it easier to find the cause of the delay.

Summary

IEPs, IESPs, RSAs, and P-3/P-4 letters are sequential steps in one process: they move mandated special education services from a written document into a child's school week. Which ones apply to your child depends largely on where your child is enrolled.

For more on what a specific service like SETSS looks like day to day, see SETSS in NYC: how enhanced-rate teacher support services work.