What type of code must be sequenced first for adverse effects under T36-T65?

When coding for adverse effects under the range T36-T65, it is essential to sequence the adverse effect code first. This is because the coding guidelines indicate that when a patient experiences an adverse effect due to medication or other substances, the code reflecting that adverse effect needs to be prioritized in the coding sequence.

The adverse effect code captures the primary reason for the encounter, which is the patient's reaction to the substance, rather than any other conditions that may also be present. This helps in clarifying the context of care and ensures that the data accurately reflects the patient's health status related to medication use.

Additionally, sequencing the adverse effect code first enhances the clarity of medical records, facilitating better treatment planning and evaluation of outcomes related to medication management. This approach aligns with the coding rules that prioritize the resolution or identification of issues that prompted an encounter, ensuring appropriate reimbursement and data reporting.