I44.5 — Left posterior fascicular block

Billable

Is I44.5 billable?

Yes — I44.5 is billable for FY2027. I44.5 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. I44.5 may be submitted for encounters from October 1, 2026 through September 30, 2027.

I44.5 at a glance

Code	I44.5
Description	Left posterior fascicular block
Billable	Yes
Code set	ICD-10-CM FY2027
Valid for encounters	October 1, 2026 – September 30, 2027

What Medicare edits apply to I44.5?

The Medicare Code Editor screens inpatient claims before they are grouped. These edits name I44.5 directly.

Questionable as an admission diagnosis — MCE edit 8

CMS does not consider this code, on its own, sufficient justification for admission to an acute care hospital when reported as the principal diagnosis.

Which MS-DRGs does I44.5 group to?

I44.5 sits in MDC 05 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

308Cardiac Arrhythmia and Conduction Disorders with MCCmedical
309Cardiac Arrhythmia and Conduction Disorders with CCmedical
310Cardiac Arrhythmia and Conduction Disorders without CC/MCCmedical

How is I44.5 listed in the Alphabetic Index?

These are the routes through the Alphabetic Index that lead to I44.5. They show the wording a clinician may have documented, which often differs from the Tabular description.

Block, blocked › fascicular › posterior
Block, blocked › bundle-branch › left › hemiblock › posterior

Excludes2 — not included here — inherited from Chapter 9

The conditions below are not part of I44.5, but a patient may have both at the same time. When documentation supports it, I44.5 and the excluded code may both be reported.

certain conditions originating in the perinatal period (P04-P96)
certain infectious and parasitic diseases (A00-B99)
complications of pregnancy, childbirth and the puerperium (O00-O9A)
congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
endocrine, nutritional and metabolic diseases (E00-E88)
injury, poisoning and certain other consequences of external causes (S00-T88)
neoplasms (C00-D49)
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
systemic connective tissue disorders (M30-M36)
transient cerebral ischemic attacks and related syndromes (G45.-)

How long has I44.5 existed?

I44.5 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.

Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.