Specific code 2011 ICD-9-CM Diagnosis Code 318.1
Severe mental retardation
  • Short description: Severe mental retardat.
  • ICD-9-CM 318.1 is a billable medical code that can be used to indicate a diagnosis on a reimbursement claim, however, 318.1 should only be used for claims with a date of service on or before September 30, 2015. For claims with a date of service on or after October 1, 2015, use an equivalent ICD-10-CM code (or codes).
  • You are viewing the 2011 version of ICD-9-CM 318.1.
  • More recent version(s) of ICD-9-CM 318.1: 2012 2013 2014 2015.
Convert to ICD-10-CM: 318.1 converts directly to:
  • 2015/16 ICD-10-CM F72 Severe intellectual disabilities
Approximate Synonyms
  • Intellectual disability, severe
  • Severe intellectual disability
  • Severe mental retardation (I.Q. 20-34)
Applies To
  • IQ 20-34
  • Severe mental subnormality
ICD-9-CM Volume 2 Index entries containing back-references to 318.1:
  • IQ
    • 20-34 318.1
  • Mental - see also condition
    • subnormality (see also Retardation, mental) 319
  • Retardation
    • mental 319
      • borderline V62.89
      • mild, IQ 50-70 317
      • moderate, IQ 35-49 318.0
      • profound, IQ under 20 318.2
      • severe, IQ 20-34 318.1
  • Subnormal, subnormality
    • mental (see also Retardation, mental) 319
ICD-9-CM codes are used in medical billing and coding to describe diseases, injuries, symptoms and conditions. ICD-9-CM 318.1 is one of thousands of ICD-9-CM codes used in healthcare. Although ICD-9-CM and CPT codes are largely numeric, they differ in that CPT codes describe medical procedures and services. Can't find a code? Start at the root of ICD-9-CM, check the 2011 ICD-9-CM Index or use the search engine at the top of this page to lookup any code.