Intellectual and Developmental Disabilities (IDD) Assessments

Offer objective, conflict-free assessments

We conduct a variety of specialized screenings, assessments, evaluations, and reviews to accurately determine care and service needs for individuals. These services are conducted in a range of community settings and for all populations, including children, adults, elderly, and persons with physical, behavioral, intellectual, and developmental disabilities.

We are the national leader in independent, person-centered assessment methodologies, expert consultation with rate setting processes, and knowledgeable support with all stakeholders. With expertise and training in several uniform assessment protocols, our Intellectual and Developmental Disabilities (IDD) assessment projects are implemented with fidelity, independence, cost-effectiveness, responsiveness, and data integrity.

Whether using the Supports Intensity Scale®  for Adults (SIS-A) or Supports Intensity Scale®  for Children (SIS-C), Inventory for Client and Agency Planning (ICAP), interRAI, or other IDD assessment tools, Maximus partners with states to:

  • Design uniform assessment programs that maintain federal compliance
  • Ensure assessments are administered systematically, independently, and transparently
  • Track and provide reporting on a wide range of variables
  • Deliver accurate assessment data to assure Individual Support Plans (ISPs) are fair, equitable, and based on objective need
  • Complete person-centered assessments focused on support needs
  • Work with assessors who have years of professional experience working with individuals with IDD and are free from conflict of interest

Our clinical expertise is bolstered by our assessment technology...

Our highly efficient web-based IDD assessment data management system give states and providers ready access to our comprehensive demographic and assessment information. Information is accessible 24/7 and real-time—providing access to the entire history of an individual’s IDD assessment experience at your fingertips.

Accessible and flexible

States and providers need reliable and timely access to assessment, rate and support information to authorize, plan, and ensure essential care and supports for individuals with intellectual and developmental disabilities (IDD). In addition, states need access and flexibly to analyze assessment and supports needs data for reporting, planning and forecasting.


As states and providers alike work to optimize resources for individuals with disability, data has become the new currency driving successful transitions from traditional to innovative, balanced, and sustainable support systems to meet the needs of persons with IDD.

Powerful and reliable

Our IDD assessment projects are fully supported by data capture, data analytic, and data dissemination functionality. By ensuring meaningful data can be accessed in powerful and flexible ways, we offer stakeholders reliable information for making IDD decisions and taking actions that best serve the needs of the individuals assessed.

...and backed by our commitment to be fair and unbiased

With each IDD assessment project, we focus on several key objectives to provide the highest quality of services, integrity, and independence to ensure that:

  • Each and every interview is fair, equitable, and valid
  • Assessments accurately represent each individual’s support needs reliably, fairly, and without the presence or perception of bias
  • The assessment is conducted by an IDD expert who is committed to person-centered standards
  • Individuals with IDD have maximal opportunity to lead the best life possible