Listing code
13.18
Adult (Part A)
Body system
13.00
Cancer (malignant neoplastic diseases)
Subsections
4
Lettered criteria paths
Step in evaluation
3 of 5
Listing match approves the claim
SSA listing text and criteria
Large intestine (from ileocecal valve to and including anal canal).
Subsection A
Adenocarcinoma that is inoperable, unresectable, or recurrent. OR
Subsection B
Squamous cell carcinoma of the anus, recurrent after surgery. OR
Subsection C
With metastases beyond the regional lymph nodes. OR
Subsection D
Small-cell (oat cell) carcinoma.
Source: SSA Blue Book listing 13.18. Last synced 2026-05-04.
Where claims under 13.18 usually fail
A frequent failure mode is not matching the disease scenario to the lettered subsections, for example treating a case of recurrent anal squamous cell carcinoma as qualifying under the adenocarcinoma language in Subsection A. Another common issue is focusing only on the diagnosis term without showing the needed extent, especially for Subsection C where the cancer must have metastases beyond the regional lymph nodes. Some claims fall short when the primary cancer site is unclear but the medical records do not provide documented sites of metastasis to evaluate the impairment. Another pitfall is assuming imaging alone proves the listing without the medical evidence needed to specify the type and extent of the primary, recurrent, or metastatic lesion.
Medical evidence that strengthens this claim
SSA needs medical evidence that specifies the type, extent, and site of the primary, recurrent, or metastatic lesion for 13.18. For operative procedures such as biopsy or needle aspiration, SSA generally needs a copy of both the operative note and the pathology report. If those cannot be obtained, SSA accepts summaries of hospitalization or other medical reports, and these summaries should include details of findings at surgery and, when appropriate, pathological findings. In situations where recurrence, persistence, progression, response to therapy, or significant post-therapeutic residuals matter, SSA may need evidence about those issues, especially because the cancer criteria can depend on recurrence patterns like "recurrent after surgery" (Subsection B) or inoperable/unresectable or recurrent disease (Subsection A).
What happens if your records do not meet this listing
If the criteria in Subsections A through D for 13.18 are not fully met, the claim does not end automatically. Step 4 and Step 5 evaluate whether the person can do past work and other work based on the residual functional capacity, even when the listing is not met. In other words, a mismatch with the exact 13.18 lettered scenario can still lead to a decision later based on functional limits rather than only the cancer label.
Work activity and the SGA gate for this condition
Work activity is generally limited during the early phase of an SSDI claim, because substantial work activity can block eligibility. After a decision is made, continued work attempts are evaluated against the relevant work activity rules, and eligibility may be affected depending on whether work activity remains at a substantial level. This listing's qualifying patterns like inoperable or unresectable adenocarcinoma (13.18A) or metastases beyond regional lymph nodes (13.18C) often come with severe effects, but the specific impact on the ability to work is still evaluated in the disability decision process.
Listing 13.18 FAQ
Questions that come up repeatedly for large intestine (from ileocecal valve to and including anal canal) disability claims.