Error of Omission vs Commission in Medical Malpractice Cases
Posted on May 13, 2026 written by Jane Paulson in Medical Malpractice
Key Takeaways
- Omission errors involve failing to take a necessary medical step.
- Commission errors involve taking an improper or incorrect action.
- Both are evaluated under the same medical standard of care.
- Malpractice requires proof that the error caused actual harm.
- Claims depend on showing that the error directly caused injury.
Medical care depends on careful judgment, attention to detail, and timely decisions. When something goes wrong, the impact can be serious and, at times, long-lasting. Many claims turn on the distinction between error of omission vs commission, a concept that often shapes how liability is analyzed. Some cases arise because a necessary step was never taken, while others involve an action that should not have occurred. As Portland medical malpractice lawyers, we evaluate these situations by closely reviewing the facts and the standard of care, including matters handled by Paulson Coletti.
In a clinical setting, patient harm may occur when a provider fails to take an essential step or takes an incorrect action, such as prescribing the wrong medication or overlooking a known risk. Both types of errors can affect outcomes, and omissions are often harder to identify because they involve something that did not happen when it should have.
Call Us (503) 226-6361 What Is an Error of Omission in Medical Care
An omission error arises when a provider fails to perform a step that reasonable care would require at that moment. It can take the form of a missed diagnosis, a failure to order appropriate testing, or a failure to follow up on symptoms that called for closer attention.
These lapses often occur in busy clinical settings where small details can carry significant weight. Legally, the focus is straightforward: would a similarly trained provider, given the same information, have taken additional action? When that step is not taken, the consequences can include delayed care, worsening conditions, or complications that could have been avoided.
What Is an Error of Commission in Healthcare
An error of commission involves taking a step that falls outside accepted medical practice. This may include performing the wrong procedure, prescribing medication that conflicts with a patient’s history, or choosing a treatment approach that does not fit the patient’s condition.
Because these cases involve an affirmative act, they are often easier to identify. Even so, the analysis requires more than pointing to the mistake. It must be shown that the decision departed from what reasonable care would require and that the action contributed in a meaningful way to the patient’s injury.
Why Both Types of Errors Can Lead to Serious Harm
Whether the issue stems from inaction or an improper decision, both can lead to serious consequences. A missed diagnosis may allow a condition to worsen over time, while an incorrect procedure can cause immediate harm or complications.
According to the FDA Safe Use Initiative, preventable medical errors continue to pose a significant concern in patient care, particularly when safeguards fail to catch mistakes before they affect the patient. This highlights the importance of recognizing both omission and commission errors when evaluating harm.
Key Differences Between Omission and Commission Errors
The difference between omission and commission centers on whether the issue involves a failure to act or an action that should not have been taken. In omission cases, a necessary step is missing. In commission cases, the provider takes a step that falls outside accepted care.
From a legal perspective, both are evaluated under the same standard of care. The central question remains whether the provider’s conduct, whether by action or inaction, fell below what is reasonably expected. Although the nature of the mistake differs, the framework for determining responsibility remains consistent.
When Medical Errors Become Malpractice in Oregon
Not every medical mistake rises to the level of malpractice. Under Oregon law, a claim must show that a provider owed a duty of care, failed to meet that duty, and caused harm.
This means both omission and commission errors must be tied to a measurable injury. A delayed diagnosis that leads to complications or an improper treatment that worsens a condition may meet this standard when supported by medical evidence.
According to the NCBI, identifying the causes of medical errors often requires careful review of clinical decisions and broader system factors. That level of review plays an important role in determining whether malpractice occurred.
Examples of Omission and Commission in Real Cases
Examples help clarify how these issues arise in practice. An omission may involve a physician failing to recognize signs of a post-surgical infection, allowing the condition to progress. Another example could be failing to review a patient’s medical history before making treatment decisions.
In contrast, a commission error may involve administering the wrong medication dosage or performing a procedure on the wrong site. While these situations may appear more direct, they still require a careful review to determine how the action caused harm.
Each case depends on its own facts, and the outcome often turns on how the conduct affected the patient’s condition.
How to Prove a Medical Malpractice Claim Based on These Errors
Establishing a claim based on error of omission vs commission requires a clear and methodical approach. Medical records, expert opinions, and a detailed timeline of care all contribute to building the case.
The process involves identifying what a reasonably competent provider would have done in the same situation and comparing that to the care that was actually provided. In omission cases, the focus is on what should have been done. In commission cases, the focus shifts to why the action taken was not appropriate.
Causation is also essential. It must be shown that the error had a direct impact on the patient’s injury, rather than being incidental.
Speak With a Portland Medical Malpractice Lawyer About Your Case
Claims involving error of omission vs commission often require careful review of both medical records and legal standards. At Paulson Coletti, we work with individuals in Portland to evaluate the circumstances, determine whether negligence may be involved, and pursue appropriate legal action when warranted.
Call 503-226-6361 to discuss your situation and explore your legal options.
At Paulson Coletti, justice is our mission. As experienced trial attorneys, we fight for injury victims across Oregon and Washington, holding negligent parties accountable. With a proven track record in and out of the courtroom, we are dedicated to securing fair compensation for our clients. We take a client-centered approach, focusing on cases we believe in and delivering results that matter. No fees unless we win—because justice should never come with financial risk.Paulson Coletti
Trial Attorneys PC