An evaluation by a developmental pediatrician is
usually covered all or in part by insurance. There are often waitlists for these appointments, so go ahead and schedule an appointment at KKI and Children's. If there are still issues with your child recognizing numbers/letters, take the first appointment available and cancel the other. If the issue resolves, cancel both appointments.
An educational evaluation called a neuropsychological evaluation or psycho-educational evaluation is usually
not covered by insurance b/c it is not considered a "medical" need but an "educational" one. Depending on your insurance they may be covered in part.
Technically, under the Individuals with Disabilities Education Act (IDEA) and Free Appropriate Public Education Act (FAPE) , the public school can evaluate your child at no cost and provide services. Contact your local public elementary school principal and request an evaluation in writing outlining your child's current issue--letter and number recognition at age 4.
A child who is found to need accommodations and/or services in school like speech or occupational therapy will be granted what's called a 504 or an IEP (Individualized Educational Plan). The Wrights Law website can give you more info on this process:
http://www.wrightslaw.com