ICD-10 code for heart block

The ICD-10-CM code for heart block is I45.9 (Conduction disorder, unspecified). The official index lists 8 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on I45.9.

Within I45, choose I45.9 (Conduction disorder, unspecified) only when documentation doesn't support a more specific option: right fascicular block (I45.0), other and unspecified right bundle-branch block (I45.1), Bifascicular block (I45.2), Trifascicular block (I45.3), nonspecific intraventricular block (I45.4), other specified heart block (I45.5), Pre-excitation syndrome (I45.6) and other specified conduction disorders (I45.8).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 308 (Cardiac Arrhythmia and Conduction Disorders with MCC, relative weight 1.1806), DRG 309 (Cardiac Arrhythmia and Conduction Disorders with CC, relative weight 0.7316) and DRG 310 (Cardiac Arrhythmia and Conduction Disorders without CC/MCC, relative weight 0.568), in MDC 05 (Diseases and Disorders of the Circulatory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.