Patient presents with a complaint of mouth sore or oral lesion.  Onset, duration, location, characteristics, and associated symptoms such as pain, burning, bleeding, difficulty swallowing odynophagia, or altered taste were documented.  Clinical examination revealed a single or multiple mouth sores.  Lesion morphology was described including size, shape, color, texture, and the presence or absence of induration, erythema, ulceration, or exudate.  Differential diagnoses considered include aphthous ulcer canker sore, cold sore fever blister oral herpes, oral thrush candidiasis, leukoplakia, erythroplakia, traumatic ulcer, and squamous cell carcinoma.  Location of the mouth sore tongue, lip, gums, palate, buccal mucosa was noted.  The patient's medical history, including relevant conditions such as diabetes, autoimmune disorders, nutritional deficiencies, recent infections, and medication use, was reviewed.  Etiology of the mouth sore was assessed, considering potential contributing factors such as trauma, infection, inflammation, nutritional deficiencies, or systemic disease.  Treatment plan may include topical or systemic medications, oral hygiene instructions, dietary modifications, and pain management strategies.  Patient education regarding oral health and prevention of recurrence was provided.  Follow-up care was scheduled as needed to monitor healing progress and address any complications.  ICD-10 codes for mouth sores such as K12.0, K13.2, B37.0, K13.7, R58.1 were considered based on the specific diagnosis.  Medical billing and coding guidelines for oral lesions were adhered to for accurate reimbursement.