2026 ICD-10-CM Diagnosis Code T38.995AAdverse effect of other hormone antagonists, initial encounter
T38.995A is a billable ICD-10-CM diagnosis code for adverse effect of other hormone antagonists, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 917 through 918. The code is not accepted as a principal diagnosis by the Medicare Code Editor. Coders also document this condition as estrogen antagonist adverse reaction. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Adverse effects of drugs and medicaments, initial encounter.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for T38.995A.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Estrogen antagonist adverse reaction
- Octreotide adverse reaction
- Trilostane adverse reaction
Coding GuidelinesGuidance
When coding an adverse effect of a drug that has been correctly prescribed and properly administered, assign the appropriate code for the nature of the adverse effect followed by the appropriate code for the adverse effect of the drug.
The appropriate 7th character is to be added to each code from block Poisoning by, adverse effect of and underdosing of hormones and their synthetic substitutes and antagonists, not elsewhere classified (T38). Use the following options for the applicable episode of care:
- A - initial encounter
- D - subsequent encounter
- S - sequela
Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Octreotide
a potent, long-acting synthetic somatostatin octapeptide analog that inhibits secretion of growth hormone and is used to treat hormone-secreting tumors; diabetes mellitus; hypotension, orthostatic; hyperinsulinism; hypergastrinemia; and small bowel fistula.Receptors, Somatostatin
cell surface proteins that bind somatostatin and trigger intracellular changes which influence the behavior of cells. somatostatin is a hypothalamic hormone, a pancreatic hormone, and a central and peripheral neurotransmitter. activated somatostatin receptors on pituitary cells inhibit the release of growth hormone; those on endocrine and gastrointestinal cells regulate the absorption and utilization of nutrients; and those on neurons mediate somatostatin's role as a neurotransmitter.Somatostatin
a 14-amino acid peptide named for its ability to inhibit pituitary growth hormone release, also called somatotropin release-inhibiting factor. it is expressed in the central and peripheral nervous systems, the gut, and other organs. srif can also inhibit the release of thyroid-stimulating hormone; prolactin; insulin; and glucagon besides acting as a neurotransmitter and neuromodulator. in a number of species including humans, there is an additional form of somatostatin, srif-28 with a 14-amino acid extension at the n-terminal.Somatostatin-28
a 28-amino acid peptide with the same biological activities of somatostatin-14 but with a 14-amino acid extension at the n-terminal. srif-28 is the major form of somatostatin in the gastrointestinal tract.Somatostatinoma
a somatostatin-secreting tumor derived from the pancreatic delta cells (somatostatin-secreting cells). it is also found in the intestine. somatostatinomas are associated with diabetes mellitus; cholelithiasis; steatorrhea; and hypochlorhydria. the majority of somatostatinomas have the potential for metastasis.Somatostatin-Secreting Cells
endocrine cells found throughout the gastrointestinal tract and in islets of the pancreas. d cells secrete somatostatin that acts in both an endocrine and paracrine manner. somatostatin acts on a variety of tissues including the pituitary gland; gastrointestinal tract; pancreas; and kidney by inhibiting the release of hormones, such as growth hormone; gastrin; insulin; and renin.
Table of Drugs and ChemicalsClinical
Substances in the Table of Drugs and Chemicals that reference this code family. Always confirm in the Tabular List before coding.
Patient EducationClinical
Drug Reactions
Most of the time, medicines make our lives better. They reduce aches and pains, fight infections, and control problems such as high blood pressure or diabetes. But medicines can also cause unwanted reactions, such as drug interactions, side effects, and allergies.
The full article covers:
- What is a drug interaction?
- What are side effects?
- What are drug allergies?
- How can I stay safe when taking medicines?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert T38.995A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T38.995AOverview
Is T38.995A (Adverse effect of other hormone antagonists) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report adverse effect of other hormone antagonists, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in T38.995A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for adverse effect of other hormone antagonists, such as an emergency visit or first evaluation.
What MS-DRG does T38.995A group to?
On inpatient claims, adverse effect of other hormone antagonists, initial encounter maps to MS-DRG 917, 918, with relative weights from 0.8571 to 1.5684 depending on complications. Higher weights mean higher Medicare reimbursement.
Can T38.995A be a principal diagnosis?
No. The Medicare Code Editor rejects this code as a principal diagnosis because adverse effect of other hormone antagonists, initial encounter describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.
What is the ICD-9 equivalent of T38.995A?
Under the General Equivalence Mappings, adverse effect of other hormone antagonists, initial encounter converts to ICD-9-CM 995.29 (adv eff med/biol NEC/NOS) and E932.9 (adv eff hormones NEC/NOS). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
