Read enough OWCP denials and a pattern appears. The claims examiner almost never says the injury did not happen. The letter says the medical evidence is insufficient to establish causal relationship, or that the physician's opinion is not rationalized, or that the diagnosed condition has not been connected to the accepted employment factors.
In other words: the treatment may have been excellent and the claim still fails on paper. Fixing that is a documentation discipline, and it is learnable.
What OWCP means by a "rationalized" opinion
A rationalized medical opinion does four things. It identifies the diagnosis with specificity. It identifies the specific employment factors — the exact duties, exposures or event, not "work." It explains the mechanism by which those factors produced that diagnosis. And it gives reasoning that addresses alternatives, including pre-existing findings.
A statement like "the patient's shoulder pain is work related" satisfies none of that. It is a conclusion with the reasoning removed, and a claims examiner is instructed to treat it as insufficient.
- Diagnosis, stated precisely and supported by findings.
- The employment factors, described in the duties' own terms.
- The mechanism linking factor to diagnosis, anatomically.
- Reasoning that addresses degenerative or prior findings and explains apportionment.
- A clear statement of the physician's degree of certainty.
A worked example: repetitive overhead work
Weak: "Rotator cuff tendinopathy, work related, patient does overhead work."
Rationalized: "Diagnosis is right supraspinatus tendinopathy with a partial-thickness tear on MRI. The employee sorts and lifts parcels averaging 15 to 40 pounds from waist level to overhead shelving roughly 200 times per shift, five shifts per week, for eleven years. Repetitive forceful overhead elevation in that range produces subacromial impingement and progressive cuff tendon degeneration through repeated compression of the tendon beneath the acromion. The MRI also shows mild acromioclavicular arthrosis, which is age-consistent and asymptomatic on examination; it does not explain the localized supraspinatus findings or the positive impingement testing. Within reasonable medical certainty, the described employment duties are the cause of the diagnosed condition."
Same physician, same patient, same visit length. The second version is what a claim is built on.
The CA-20: where the causation opinion belongs
The CA-20 attending physician's report is the natural home for that reasoning, and the section asking whether the condition was caused or aggravated by employment activity is not a yes/no box in practice. Attaching a narrative that supplies the four elements above is the difference between an accepted claim and a development letter.
Where a pre-existing condition was made worse, say so explicitly and characterize it — temporary aggravation, permanent aggravation, or acceleration — because those have different consequences under FECA.
The CA-17: the form agencies actually use day to day
The CA-17 duty status report is a two-sided document. The agency describes the regular job's physical requirements; the physician states what the employee can currently do. It is the form that determines whether someone works limited duty or sits at home.
Vague completion is the norm and the problem. "No heavy lifting" gives an agency nothing to place someone into. Weights with zones and frequencies, postural time limits, specific prohibited tasks, and a review date give a return-to-work coordinator a real assignment to build.
- Answer every capability line — blanks read as unanswered, not as unrestricted.
- Use pounds and frequencies, not adjectives.
- Address sitting, standing, walking, climbing, driving and reaching separately.
- Give an expected duration and a follow-up date.
- Keep it consistent with the office note from the same visit; contradictions get flagged.
Responding to a development letter
A development letter is not a denial. It is a request, usually with a deadline measured in weeks, for the specific evidence the file lacks. Read it literally: it will name what is missing — factual evidence of the employment factors, a diagnosis, or a rationalized causation opinion.
Respond to each numbered item in order, in writing, and reference the enclosures. A supplemental narrative from the treating physician that tracks the letter's own language is far more effective than resending the same records that already failed.
Deadlines in development letters are real. A late response converts a fixable evidentiary gap into a denial you then have to appeal.
Practical habits that prevent most denials
- Capture the mechanism in the employee's own words at the first visit, with dates.
- Document objective findings at every visit, not just symptom reports.
- Write the causation narrative while the examination is fresh, not months later.
- Never let a state-style work-status slip substitute for a CA-17.
- Reconcile imaging that shows degenerative change instead of ignoring it.
- Keep the office note, the CA-17 and the CA-20 telling one consistent story.
Frequently asked questions
Talk to a clinic that handles these claims every day
Our Kansas City and St. Louis clinics evaluate state and federal work injuries, write job-specific restrictions, and prepare the documentation adjusters, agencies and TPAs need.
This article is general information about claim procedure and is not legal advice or a substitute for individual medical evaluation.