If you’re dealing with a long-term disability claim, a denial can feel personal, confusing, and financially destabilizing all at once. Many people assume the outcome turns mostly on whether they are truly sick or injured. In real life, LTD claims often rise or fall on documentation, deadlines, policy language, and how limitations are described in the file.
That’s especially true in employer-provided disability plans governed by ERISA, where the claim file often becomes the center of the dispute. The U.S. Department of Labor’s claims-procedure rules give disability claimants important protections, including at least 180 days to appeal an adverse benefit determination and access to information used in the decision process, but those protections only help if the claimant knows how to use them well (Department of Labor, Cornell Law School’s Legal Information Institute).
In this post, you’ll learn seven common LTD claim mistakes that often make denials more likely, why insurers focus on them, and what an attorney may look for when evaluating whether a denial could have been avoided or challenged more effectively. If you want a broader foundation first, it may help to start with this overview of how LTD claims, medical proof, own-occupation language, and ERISA issues fit together.
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Long-term disability carriers do not evaluate claims the same way a treating doctor evaluates a patient. A physician may focus on diagnosis, treatment, symptom progression, and clinical judgment. An LTD carrier often focuses on policy definitions, exclusions, timing, functional capacity, consistency, and whether the file contains enough evidence to support occupational restrictions.
That difference matters. The Social Security Administration, for example, explains that functional capacity is assessed from all relevant medical and other evidence, including treatment history, symptoms, daily activities, work attempts, side effects, and medical source statements (SSA regulation, SSA POMS). LTD carriers often use a similar functional-analysis mindset, even though the governing policy language may differ from Social Security’s rules.
In other words, many denials are not framed as “we don’t believe you’re sick.” They are framed more narrowly: “the records do not establish disabling restrictions,” “the policy definition is not met,” “the evidence is inconsistent,” or “the claimant did not provide sufficient proof.”
One of the most common mistakes is believing that a diagnosis by itself settles the claim.
For LTD purposes, a diagnosis often starts the conversation rather than ending it. The key issue is usually how the condition limits work-related function. Can the person sustain concentration? Sit for prolonged periods? Use their hands repetitively? Meet attendance expectations? Travel? Handle deadlines? Maintain pace? Recover from exertion?
This issue shows up often in conditions that may be serious but harder to capture with a single lab result or imaging study, such as autoimmune disease, migraine, chronic pain, dysautonomia, fibromyalgia, post-viral illness, and some psychiatric conditions. Federal health agencies now recognize that conditions like Long COVID can involve fluctuating symptoms and substantial activity limitations. The CDC reports that about 1 in 5 adults with Long COVID have experienced significant limitations in daily activity, and its clinical guidance notes that post-exertional symptom worsening can follow even minor physical or mental exertion (CDC, CDC clinical guidance).
Here’s what this often means in an LTD claim: the carrier may not dispute the diagnosis, but still deny benefits because the file does not clearly connect the diagnosis to specific, work-relevant restrictions and limitations.
An attorney reviewing a denial often looks for gaps such as: