R00.0Tachycardia, unspecified

R00.0 is the ICD-10-CM diagnosis code for tachycardia, unspecified. It belongs to category R00 (abnormalities of heart beat), block R00-R09 (symptoms and signs involving the circulatory and respiratory systems) and chapter 18 (symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within R00, choose R00.0 (Tachycardia, unspecified) only when documentation doesn't support a more specific option: bradycardia, unspecified (R00.1), Palpitations (R00.2), other abnormalities of heart beat (R00.8) and unspecified abnormalities of heart beat (R00.9).

Don't report R00.0 together with the conditions in its Excludes1 note: inappropriate sinus tachycardia, so stated (I47.11), neonatal tachycardia (P29.11) and paroxysmal tachycardia (I47.-).

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), DRG 310 (Cardiac Arrhythmia and Conduction Disorders without CC/MCC, relative weight 0.568), DRG 791 (Prematurity with Major Problems, relative weight 4.1075) and DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), in MDC 05 (Diseases and Disorders of the Circulatory System) and MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 785.0 (tachycardia, unspecified).