Patient presents with symptoms suggestive of testosterone deficiency (hypogonadism), including fatigue, decreased libido, erectile dysfunction, and reduced muscle mass.  He reports a gradual onset of these symptoms over the past year.  Review of systems reveals difficulty concentrating, depressed mood, and decreased energy levels.  Past medical history is significant for hypertension, managed with lisinopril.  Family history is noncontributory.  Physical examination reveals normal testicular size and no gynecomastia.  Initial laboratory evaluation includes a morning serum total testosterone level, free testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH).  Differential diagnosis includes primary hypogonadism, secondary hypogonadism, and age-related decline in testosterone.  Based on the patient's clinical presentation and pending laboratory results, the current assessment is consistent with possible male hypogonadism.  A treatment plan will be formulated following review of laboratory data and may include testosterone replacement therapy (TRT), lifestyle modifications such as diet and exercise, and management of comorbid conditions.  Patient education will address the benefits and risks of testosterone therapy, potential side effects, and the importance of follow-up monitoring of testosterone levels, hematocrit, and prostate-specific antigen (PSA).  ICD-10 code E29.1 (Testicular hypofunction) or E23.0 (Hypogonadotropic hypogonadism) may be applicable depending on laboratory results.  CPT codes for laboratory testing and follow-up visits will be documented accordingly. The patient was advised to return for follow-up in four weeks to review laboratory results and discuss treatment options.