| Z55.0 | Illiteracy and low-level literacy | BILLABLE CODE |
| Z55.1 | Schooling unavailable and unattainable | BILLABLE CODE |
| Z55.2 | Failed school examinations | BILLABLE CODE |
| Z55.3 | Underachievement in school | BILLABLE CODE |
| Z55.4 | Educational maladjustment and discord with teachers and classmates | BILLABLE CODE |
| Z55.5 | Less than a high school diploma | BILLABLE CODE |
| Z55.6 | Problems related to health literacy | BILLABLE CODE |
| Z55.8 | Other problems related to education and literacy | BILLABLE CODE |
| Z55.9 | Problems related to education and literacy, unspecified | BILLABLE CODE |
