Diseases of pulp and periapical tissues (K04) ICD-10-CM
The K04 code range covers diseases of pulp and periapical tissues with 15 ICD-10-CM diagnosis codes. 12 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Codes in the K04 Range 15 codes · 12 billable
- K04 Diseases of pulp and periapical tissuesNon-billable
- K04.0 PulpitisNon-billable
- K04.01 Reversible pulpitis
- K04.02 Irreversible pulpitis
- K04.1 Necrosis of pulp
- K04.2 Pulp degeneration
- K04.3 Abnormal hard tissue formation in pulp
- K04.4 Acute apical periodontitis of pulpal origin
- K04.5 Chronic apical periodontitis
- K04.6 Periapical abscess with sinus
- K04.7 Periapical abscess without sinus
- K04.8 Radicular cyst
- K04.9 Other and unspecified diseases of pulp and periapical tissuesNon-billable
- K04.90 Unspecified diseases of pulp and periapical tissues
- K04.99 Other diseases of pulp and periapical tissues
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the K04 range.
Dental Pulp
A richly vascularized and innervated connective tissue of mesodermal origin, contained in the central cavity of a tooth and delimited by the dentin, and having formative, nutritive, sensory, and protective functions. (Jablonski, Dictionary of Dentistry, 1992)
Oral Fistula
An abnormal passage within the mouth communicating between two or more anatomical structures.
Periapical Abscess
Acute or chronic inflammation of tissues surrounding the apical portion of a tooth, associated with the collection of pus, resulting from infection following pulp infection through a carious lesion or as a result of an injury causing pulp necrosis. (Dorland, 27th ed)
Periodontal Cyst
An epithelium-lined sac containing fluid; usually found at the apex of a pulp-involved tooth. The lateral type occurs less frequently along the side of the root.
Pulpitis
Inflammation of the DENTAL PULP, usually due to bacterial infection in dental caries, tooth fracture, or other conditions causing exposure of the pulp to bacterial invasion. Chemical irritants, thermal factors, hyperemic changes, and other factors may also cause pulpitis.
Radicular Cyst
Slow-growing fluid-filled epithelial sac at the apex of a tooth with a nonvital pulp or defective root canal filling.
About the K04 Code Range
The ICD-10 code K04 identifies diseases affecting the dental pulp and the tissues surrounding the root apex, covering inflammation, degeneration, abscesses, cysts, and other conditions related to tooth pulp health. These codes are used to classify conditions such as pulpitis, necrosis, and periapical periodontitis for accurate diagnosis and treatment documentation.
This set includes specific codes for various stages and types of pulpitis: K04.01 for reversible pulpitis, which is inflammation that can be healed, and K04.02 for irreversible pulpitis, where the damage is permanent. Terms like "suppurative pulpitis" and "chronic hyperplastic pulpitis" relate back to K04.01. Necrosis of pulp, commonly called "mummified pulp," is coded under K04.1. Other codes cover pulp degeneration and abnormal hard tissue growth inside the pulp (K04.2 and K04.3). Conditions involving the periapical tissues, such as acute and chronic apical periodontitis (K04.4 and K04.5), and periapical abscesses with or without sinus tracts (K04.6 and K04.7) are also included. The ICD-10 code for radicular cyst is K04.8, referring to inflammatory cysts at the tooth root. When a specific diagnosis is unavailable, codes K04.90 or K04.99 classify unspecified or other diseases of the pulp and periapical tissues.
Questions About This Page
How many billable codes are in the K04 range?
Of the 15 codes in this range, 12 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the K04 range classify?
The range classifies diseases of pulp and periapical tissues. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
