If you have a concern about your infant or toddler's development, discuss it with your pediatrician, but also consider an Early Intervention evaluation. Your pediatrician may be able to reassure you that your child is developing typically, but if you're not convinced, this program can serve as a "second opinion", and provide developmental services if your child is indeed delayed. It's nice to be formally referred by your pediatrician, but you can self-refer if need be.
Early Intervention centers have family resource coordinators, physical therapists, occupational therapists, and speech and feeding therapists, all with expertise in early childhood development. They may draw upon your insurance, but the rest of the costs are typically covered by the state. For families in Washington State, you can get a referral to a nearby center from WithinReach, at 1-800-322-2588. I also recommend "A Family's Guide to Early Intervention in Washington State". Oregon residents can use this brochure.
For international adoptees, who often have multiple prenatal and postnatal risks, and delays from neglect and institutionalization, the decision to involve your child in early intervention is a bit trickier. The major intervention in your child's life is adoption itself, and you should expect rapid developmental catchup by virtue of your love, attention, stimulation, and nutrition. However, if your child is more delayed than other orphanage-raised children on arrival, has other known developmental risks like prenatal alcohol/drug exposures and prematurity, or is not making rapid catchup progress in the first 1-2 months home, then early intervention is recommended. Even if your child is "typically delayed", many parents don't feel comfortable doing this on their own, and want help assessing development, tracking progress, and with practical tools and guidance for their home interventions, as well as direct therapy services.