A PMHNP in an outpatient psychiatric practice is informed by the billing department that her documentation consistently supports a 99213 (low-complexity established patient visit) code, yet her visits average 40 minutes and involve complex medication management for patients with multiple comorbidities. The billing manager suggests she is significantly undercoding, which reduces clinic revenue and misrepresents the complexity of care she provides. The PMHNP wants to understand proper E/M coding for psychiatric visits. Which of the following best describes appropriate coding practices?