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I45.9

I45.9Conduction disorder, unspecified

Billable / specific codeICD-10-CM

I45.9 is a billable, specific ICD-10-CM code for conduction disorder, unspecified. It is valid for submission on a claim.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Heart block NOS
  • Stokes-Adams syndrome

Other codes that can never be billed with I45.9

These codes carry an Excludes1 note pointing at I45.9. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading I45.9 alone.

  • R55Syncope and collapse
  • I45.5Other specified heart block

Risk adjustment

I45.9 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

I45.9 is named in 7 Medicare coverage policies 7 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A56602Billing and Coding: Cardiac Rhythm Device Evaluation
  • A56781Billing and Coding: Transthoracic Echocardiography (TTE)
  • A57306Billing and Coding: Transthoracic Echocardiography (TTE)
  • A57326Billing and Coding: Electrocardiograms

How I45.9 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to I45.9.

  • Adams-Stokes disease or syndrome(-Morgagni)
  • Dropped heart beats
  • Morgagni-Stokes-Adams syndrome
  • Spens' syndrome(syncope with heart block)
  • Stokes-Adams disease or syndrome
  • Arrhythmiablock
  • Attack, attacksAdams-Stokes
  • Attack, attacksStokes-Adams
  • Block, blockedarrhythmic
  • Block, blockedcardiac
  • Block, blockedconduction
  • Block, blockedheart

Related codes at this level

Codes that share I45. If I45.9 is not quite right, the correct code is usually one of these.

Questions about I45.9

Is I45.9 a billable ICD-10-CM code?
Yes. I45.9 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does I45.9 sit in the tabular list?
Diseases of the circulatory system (I00-I99), in the block Other forms of heart disease (I30-I5A).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.