ICD-10 Code for Block

The ICD-10-CM 2027 alphabetic index lists block, blocked with the subterms below. More specific codes depend on the details documented, as listed in the official index (28 codes, 28 billable).

Index entries for Block

alveolocapillary – J84.10
arborization (heart) – I45.5
arrhythmic – I45.9
atrioventricular (incomplete) (partial) – I44.30
- with atrioventricular dissociation – I44.2
- complete – I44.2
  - congenital – Q24.6
- congenital – Q24.6
- first degree – I44.0
- second degree (types I and II) – I44.1
- specified NEC – I44.39
- third degree – I44.2
- types I and II – I44.1
auriculoventricular – see Block, atrioventricular
bifascicular (cardiac) – I45.2
bundle-branch (complete) (false) (incomplete) – I45.4
- bilateral – I45.2
- left – I44.7
  - with right bundle branch block – I45.2
  - hemiblock – I44.60
    - anterior – I44.4
    - posterior – I44.5
  - incomplete – I44.7
    - with right bundle branch block – I45.2
- right – I45.10
  - with
    - left bundle branch block – I45.2
    - left fascicular block – I45.2
  - specified NEC – I45.19
- Wilson's type – I45.19
cardiac – I45.9
conduction – I45.9
- complete – I44.2
fascicular (left) – I44.60
- anterior – I44.4
- posterior – I44.5
- right – I45.0
- specified NEC – I44.69
foramen Magendie (acquired) – G91.1
- congenital – Q03.1
  - with spina bifida – see Spina bifida, by site, with hydrocephalus
heart – I45.9
- bundle branch – I45.4
  - bilateral – I45.2
- complete (atrioventricular) – I44.2
- congenital – Q24.6
- first degree (atrioventricular) – I44.0
- second degree (atrioventricular) – I44.1
- specified type NEC – I45.5
- third degree (atrioventricular) – I44.2
hepatic vein – I82.0
intraventricular (nonspecific) – I45.4
- bundle branch
  - bilateral – I45.2
kidney – N28.9
- postcystoscopic or postprocedural – N99.0
Mobitz (types I and II) – I44.1
myocardial – see Block, heart
nodal – I45.5
organ or site, congenital NEC – see Atresia, by site
portal (vein) – I81
second degree (types I and II) – I44.1
sinoatrial – I45.5
sinoauricular – I45.5
third degree – I44.2
trifascicular – I45.3
tubal – N97.1
vein NOS – I82.90
Wenckebach (types I and II) – I44.1

How to choose the right code

Start with the main term, then pick the indented subterm that matches the documentation (type, cause, site, laterality, episode of care). Always confirm the code in the tabular list: follow its Excludes1/Excludes2, “code first” and “use additional code” notes, and add a 7th character where required.

Source: CDC/NCHS ICD-10-CM FY2027 alphabetic index.