Once you accept an IEP, the school system must provide all the services described in that plan right away, unless the IEP states that some services are to commence at a later time. Unfortunately, parents cannot always assume that this will happen. They cannot even assume that the school will tell them if services are not being delivered. Thus you need to find ways to check on service delivery and keep a journal to record days when services are not delivered. Depending on his/her cognitive and communication abilities, your child's own reports of his/her school day provide one source of information. Other ways to check on services include regularly asking the teacher or other service provider how things are going; personally observing your child's program from time to time; using a notebook to communicate back and forth with the teacher and/or other service providers; and talking regularly with the parents of other children in your child's program. In the more formal discovery procedures that apply when a dispute is in litigation, parents can obtain specific documentary and other information to determine exactly how much service the school has not delivered.
If you believe that a service is not being delivered, you should first see if the school agrees with you. School personnel may believe that the service is being delivered because they have a different concept of what the IEP requires. For example, if the IEP states, ambiguously, that a student will receive speech/language therapy in "individual/small group settings" the school might think that a therapist's occasional visits to the classroom fulfill that requirement even if s/he never directly works with the child. If you don't agree with the school system's interpretation, and the issue is important enough, you may want to formally challenge both the school system's interpretation of the IEP and its position that the service they are delivering is sufficient. In some cases you will need an educator or other professional who will state that the services being delivered are not consistent with the IEP.
In cases that warrant formal action, you will need to find out where and how to bring a complaint about noncompliance in your state. You may be able to have the situation investigated by a state-level office responsible for handling such complaints, or you may have to ask for a due process hearing. You should be able to find the appropriate route by calling your state's Department of Education (visit FEN's state resources), a local parent advocacy agency, or an attorney who concentrates in special education law. Families often find that asking for a due process hearing is the most effective way to resolve issues of noncompliance.
If the school agrees that the service has not been delivered, then the only question is how to make up for the lost service effectively. If you can agree on how many hours of services have been lost, they could be made up in any way that fits with the student's needs and learning style by, for example, doubling weekly services temporarily or providing services during vacation periods. If you have "covered" the missing services by hiring a private service provider until the school begins to deliver the service, you can seek reimbursement from the school system for that expense.
In some cases you need to be more creative. For example, if a child's time and learning capacity are already "maxed out," simply adding more hours of service in his/her ordinary school schedule probably won't work. In such cases, perhaps, you could agree to "bank" the lost services to use at a later time when there might be disagreement about the need for ongoing services. In cases involving larger issues, such as when a child is provided no services at all for a significant period, you may consider having the school agree to continue providing special education services for a period after s/he reaches the maximum age of eligibility for special education in your state. An argument can also be made in some cases for an award of damages (the law is just developing in this area).
Be sure to monitor implementation of your child's IEP, because the longer a child goes without a service, the harder it is to correct the situation effectively. It's easier to prevent non-compliance at the beginning than to fix it months later.