Patient presents with macrocytosis, defined as an increased mean corpuscular volume (MCV) above the upper limit of normal for age and sex.  Review of systems reveals possible symptoms associated with macrocytosis including fatigue, weakness, pallor, shortness of breath, dizziness, and palpitations.  Other symptoms, if present, should be documented.  Physical examination findings may include pallor, tachycardia, glossitis, or neurological signs depending on the underlying etiology.  Differential diagnosis for macrocytosis includes vitamin B12 deficiency, folate deficiency, liver disease, alcohol abuse, hypothyroidism, myelodysplastic syndromes, aplastic anemia, and certain medications.  Initial laboratory workup includes complete blood count (CBC) with MCV, peripheral blood smear, vitamin B12 levels, and folate levels.  Further testing, such as liver function tests, thyroid stimulating hormone (TSH), reticulocyte count, and bone marrow biopsy, may be indicated based on initial findings and clinical suspicion.  Medical coding will be determined based on the underlying cause of the macrocytosis.  Treatment plan will be tailored to address the specific etiology once identified.  Patient education includes discussion of dietary modifications, potential need for supplementation, and importance of follow-up care. The patient was informed about the risks, benefits, and alternatives to the proposed treatment plan and demonstrated understanding.