Specific code 2011 ICD-9-CM Diagnosis Code 331.5
Idiopathic normal pressure hydrocephalus (inph)
  • Short description: Norml pressure hydroceph.
  • ICD-9-CM 331.5 will be replaced by an equivalent ICD-10-CM code (or codes) when the United States transitions from ICD-9-CM to ICD-10-CM on October 1, 2015.
  • ICD-9-CM 331.5 is a billable medical code that can be used to specify a diagnosis on a reimbursement claim.
  • You are viewing the 2011 version of ICD-9-CM 331.5.
  • More recent version(s) of ICD-9-CM 331.5: 2012 2013 2014.
Disease Synonyms
  • Normal pressure hydrocephalus
331.5 Excludes
  • congenital hydrocephalus (742.3)
  • secondary normal pressure hydrocephalus (331.3)
  • spina bifida with hydrocephalus (741.0)
Applies To
  • Normal pressure hydrocephalus NOS
Convert to ICD-10-CM: 331.5 converts directly to:
  • 2014 ICD-10-CM G91.2 (Idiopathic) normal pressure hydrocephalus
ICD-9-CM Volume 2 Index entries containing back-references to 331.5:
  • Hydrocephalus (acquired) (external) (internal) (malignant) (noncommunicating) (obstructive) (recurrent) 331.4
    • normal pressure 331.5
      • idiopathic (INPH) 331.5
      • secondary 331.3
  • INPH (idiopathic normal pressure hydrocephalus) 331.5
ICD-9-CM codes are used in medical billing and coding to describe diseases, injuries, symptoms and conditions. ICD-9-CM 331.5 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.