ICDcodes.org
FY2027

Z55.0 — Illiteracy and low-level literacy

Billable

Is Z55.0 billable?

Yes — Z55.0 is billable for FY2027. Z55.0 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. Z55.0 may be submitted for encounters from October 1, 2026 through September 30, 2027.

Z55.0 at a glance

CodeZ55.0
DescriptionIlliteracy and low-level literacy
BillableYes
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027

What Medicare edits apply to Z55.0?

The Medicare Code Editor screens inpatient claims before they are grouped. These edits name Z55.0 directly.

Cannot be a principal diagnosis — MCE edit 9

CMS will reject this code as the principal diagnosis on an inpatient claim. It describes something other than the condition chiefly responsible for the admission.

Which MS-DRGs does Z55.0 group to?

Z55.0 sits in MDC 23 and helps define the logic of 1 MS-DRG (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

  • 951Other Factors Influencing Health Statusmedical

How is Z55.0 listed in the Alphabetic Index?

These are the routes through the Alphabetic Index that lead to Z55.0. They show the wording a clinician may have documented, which often differs from the Tabular description.

  • Illiteracy
  • Low › level of literacy
  • Problem › illiteracy (with) (related to)
  • Problem › literacy › low level (with) (related to)

Excludes1 — never code together — inherited from Z55

The conditions below can never be reported together with Z55.0 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.

  • disorders of psychological development (F80-F89)

How long has Z55.0 existed?

Z55.0 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.

Which conditions are coded to Z55.0?

What other codes are in the Z55 family? (8)