Importance: Opioid dosage tapering has emerged as a strategy to reduce harms associated with long-term opioid therapy; however, evidence supporting this approach is limited.

Question: For patients receiving stable long-term opioid therapy compared with a stable opioid dosage, what is the association of opioid dosage tapering or abrupt discontinuation with opioid overdose or suicide?

Findings: In this comparative effectiveness study of 415 123 episodes of stable long-term opioid therapy among 199 836 individuals, opioid tapering was associated with a small absolute increase in opioid overdose or suicide compared with a stable opioid dosage. No significant difference in outcomes between abrupt discontinuation and stable opioid therapy was identified.

Meaning: These findings do not support opioid dosage tapering as a strategy to reduce harms for patients receiving stable long-term opioid therapy without evidence of misuse.