ICD-10 Code D35.7: Benign neoplasm of other specified endocrine glands

Key Takeaways

ICD-10 Code D35.7 describes a benign neoplasm of other specified endocrine glands, a billable diagnosis code valid for FY 2026 claims.

D35.7 applies when the neoplasm involves an endocrine gland that is named in the clinical record but has no dedicated subcode within D35.0 through D35.6.

Four endocrine structures are excluded from the entire D35 category by Excludes1 notes: endocrine pancreas (D13.7), ovary (D27.-), testis (D29.2.-), and thymus (D15.0).

Pabau’s claims management software helps endocrinology and oncology teams submit D35.7 claims accurately with structured clinical documentation workflows.

ICD-10 Code D35.7 is a billable ICD-10-CM diagnosis code that covers benign neoplasms of endocrine glands falling outside the specifically named D35 subcodes. It applies when the treating clinician has identified the endocrine gland involved but that gland has no dedicated subcode within D35.0 through D35.6.

This reference covers everything coders, clinicians, and billing teams need to apply ICD-10 Code D35.7 correctly: its official description, billable status, Excludes1 notes, sibling codes in the D35 category, documentation requirements, and sequencing rules for FY 2026.

ICD-10 Code D35.7: Definition, billable status, and clinical description

ICD-10 Code D35.7 is a valid, billable ICD-10-CM diagnosis code for FY 2026. The CDC/NCHS ICD-10-CM web tool confirms its official description as Benign neoplasm of other specified endocrine glands. It belongs to chapter 2 of ICD-10-CM (Neoplasms, C00-D49), within block D10-D36 (Benign neoplasms, except benign neuroendocrine tumors).

The word “specified” is the operative distinction. D35.7 applies when the treating clinician has identified the precise endocrine gland involved, but that gland does not have its own dedicated subcode within D35.0 through D35.6. The code signals to payers that this is not a guess: the gland is known, just not individually enumerated elsewhere in the category.

Benign neoplasms in ICD-10-CM are, by definition, non-malignant growths. They do not invade adjacent tissue or metastasize, distinguishing them from the C-range malignant neoplasm codes. For endocrine glands, these typically include adenomas, hamartomas, and other slow-growing masses confirmed by histology or imaging. Coding D35.7 requires that the neoplasm’s benign nature is explicitly documented or pathologically confirmed, since endocrine masses carry differential diagnoses that include malignancy.

Practices using a structured patient record system can flag these documentation requirements at the point of care, reducing the risk of submitting a code that is later questioned for lack of clinical support. For related neoplasm coding references across specialties, Pabau’s diagnostic code library covers a range of code categories.

D35 category overview: Sibling codes and where D35.7 fits

D35.7 sits within the D35 parent category, which covers benign neoplasms of other and unspecified endocrine glands. Understanding the full sibling structure helps coders choose the most specific code available before defaulting to D35.7 or D35.9.

The coding decision tree is straightforward: if the gland has a dedicated D35 subcode (adrenal, parathyroid, pituitary, craniopharyngeal duct, pineal, carotid body, or paraganglia), use that specific code. If the gland is known but unlisted, use D35.7. If the gland is genuinely unidentifiable from the documentation, D35.9 applies. Defaulting to D35.9 when D35.7 is supportable is a specificity error. The AAPC Codify ICD-10-CM lookup is a useful reference for navigating the full D35 subcategory structure and checking crosswalk relationships.

Excludes1 notes for ICD-10 Code D35.7

The D35 category carries Excludes1 notes that apply to every subcode, including D35.7. These are not optional coding hints; they are hard prohibitions. An Excludes1 note means the excluded condition can never be coded simultaneously with D35.7 on the same claim.

Excludes1 conditions (cannot be coded with D35.7)

• D13.7 – Benign neoplasm of endocrine pancreas
• D27.- – Benign neoplasm of ovary
• D29.2.- – Benign neoplasm of testis
• D15.0 – Benign neoplasm of thymus

These structures have dedicated codes elsewhere in ICD-10-CM and are expressly excluded from the D35 category. A benign pancreatic neuroendocrine tumor, for instance, is coded with D13.7, never D35.7, regardless of the pancreas’s endocrine function. Misapplying D35.7 in these scenarios will generate a claim edit or denial under most payer editing systems.

What D35.7 does not include: common points of confusion

Coders occasionally attempt to apply D35.7 to thyroid gland neoplasms. The thyroid has dedicated ICD-10-CM codes outside the D35 range (D34 for benign thyroid neoplasms), so it does not belong here. Similarly, malignant endocrine neoplasms belong in the C-range malignant neoplasm codes (C73-C75), not in D35.7, even if the treating clinician initially suspected a benign lesion.

For teams working across multiple specialty areas, linking encounter forms to the right code family early in the workflow reduces rework. Digital patient intake forms can be structured to prompt clinicians for the specific endocrine site, which makes coder review faster and more accurate downstream. Practices coding across endocrine, oncology, and internal medicine often benefit from reviewing medical documentation best practices to keep clinical notes aligned with coding requirements.

Documentation requirements for ICD-10 Code D35.7

Payers consistently request additional documentation for endocrine neoplasm codes because the D35 range shares clinical territory with malignant neoplasms and uncertain behavior neoplasms (D3A range). Clear, specific notes reduce that friction significantly and support cleaner medical billing.

What clinicians must document to support D35.7

• Named endocrine gland: The clinical note must identify the specific gland by name. “Endocrine mass” alone does not support D35.7 over D35.9.
• Benign characterization: Pathology report confirming benign histology, or imaging with documented benign features (e.g., no invasion, no lymphadenopathy), must be on file.
• Exclusion of malignancy: Notes should reflect that malignancy was considered and ruled out, particularly where the gland in question is a common site for both benign and malignant tumors.
• Functional activity status: If the neoplasm is hormonally active (e.g., a functioning adenoma causing hypersecretion), ICD-10-CM guidance indicates a “Use additional code” instruction to capture the associated functional disorder. Document the hormone excess or deficiency separately.

The functional activity instruction is one of the most overlooked documentation omissions in endocrine neoplasm coding. A coder cannot add a functional activity code without clinician documentation of the hormonal effect. Practices that use a claims management software workflow can build pre-submission edits that flag encounters where a functional endocrine code is expected but missing, catching the omission before the claim leaves the practice. Teams in functional medicine and endocrinology practice management settings particularly benefit from this structured approach.

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Coding guidelines and sequencing rules for D35.7

The D35 category includes a coding convention note on etiology and manifestation sequencing. According to the CMS ICD-10-CM guidelines, when a condition has both an underlying etiology and a body-system manifestation, the etiology code is sequenced first. For D35.7 encounters, this typically arises when the endocrine neoplasm is causing a downstream endocrine disorder.

Sequencing D35.7 with functional activity codes

When a benign endocrine neoplasm at a specified site is causing a functional abnormality, sequencing depends on the clinical focus of the encounter.

• If the encounter focuses on the neoplasm itself (e.g., surgical removal, biopsy, imaging follow-up), D35.7 is the principal diagnosis.
• If the encounter focuses on managing the functional disorder caused by the neoplasm (e.g., treating hypersecretion), the functional disorder code may be principal, with D35.7 as an additional code.
• Where a “Use additional code” instruction applies for functional activity, the functional code follows D35.7 in the code sequence, not the reverse.

Uncertainty about sequencing is a common source of coding errors when providers handle both the neoplasm and the functional consequence in a single encounter. For practices managing complex endocrine cases, reviewing how to code co-occurring endocrine disorders such as hypothyroidism and how sequencing rules apply across ICD-10-CM categories is worthwhile.

Using the ICD-10-CM Alphabetic Index for D35.7

Coders should always verify D35.7 through the ICD-10-CM Alphabetic Index before applying it. The Index entry path is: Neoplasm, neoplastic > endocrine gland NEC (not elsewhere classified) > benign. “NEC” in the Index corresponds to the “other specified” language in the Tabular List, confirming that D35.7 is the correct destination for a named-but-unlisted gland. Never assign D35.7 based solely on a description search without confirming the Index and Tabular entries align.

ICD-10 Code D35.7 vs. D35.9: Choosing the right code

The choice between D35.7 and D35.9 comes down to one question: does the clinical documentation name the specific endocrine gland involved?

D35.9 is never wrong when the gland is genuinely unknown. But querying the clinician when the gland is identifiable from imaging or pathology but not documented in the assessment is always appropriate. The extra specificity that supports D35.7 over D35.9 protects against payer downcoding and supports medical necessity more clearly.

For practices working in dermatology and skin oncology practice software environments where skin adnexal tumors occasionally overlap with endocrine classification questions, the distinction between specified and unspecified is equally critical. Coders dealing with benign tumors at other sites may also find ICD-10 coding for a benign neoplasm of the meninges a useful adjacent reference for benign-neoplasm sequencing principles.

Conclusion

Endocrine neoplasm coding errors typically stem from two places: insufficient clinical documentation and poor specificity choices. ICD-10 Code D35.7 is the right code when the gland is known but unlisted in D35.0 through D35.6, and using it correctly protects claims from the specificity-related denials that D35.9 can attract.

Pabau’s practice management platform helps endocrinology and oncology practices build documentation and coding workflows that catch these distinctions before submission — the foundation of efficient healthcare revenue cycle management. Teams managing multi-specialty coding across longevity and metabolic health practice software environments will find structured workflows particularly valuable for endocrine neoplasm encounters. To see how Pabau supports clean claim submission across complex diagnostic categories, book a demo.

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