The CPT® codes that describe obstetrical services start at 59000.  There are codes for delivery that include the entire obstetrical package, from pre-natal, through delivery, to post-partum.  These global codes are used when the practice performs all of the services.  

There are codes that also describe components of the whole, to be used when less than the comprehensive service was provided.  These include pre-natal services, the delivery, and postpartum care.  If a patient transfers from one practice to another or changes insurance.  These codes start with 59400 thorugh 59622.  If there are only three pre-natal visits, use E/M codes.  However, for a patient who is seen four or more times, use the appropriate codes in this section.  These codes are billed without modifiers.