2027 ICD-10-CM Diagnosis Code T36.0X2APoisoning by penicillins, intentional self-harm, initial encounter
T36.0X2A is a billable ICD-10-CM diagnosis code for poisoning by penicillins, intentional self-harm, 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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 917 through 918. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under External cause codes: intent of injury, self-harm; External cause codes: poisoning by drug; and Poisoning by drugs, initial encounter.
For Medicare Advantage risk adjustment, T36.0X2A maps to CMS-HCC Category 155 (Major Depression, Moderate or Severe, without Psychosis) under the V28 model, adding a risk factor of about 0.299 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
T36.0X2A maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Ampicillin overdose
- Carbenicillin overdose
- Cloxacillin overdose
- Flucloxacillin overdose
- Flucloxacillin poisoning
- Intentional ampicillin overdose
- Intentional ampicillin poisoning
- Intentional carbenicillin overdose
- Intentional carbenicillin poisoning
- Intentional cloxacillin overdose
- Intentional cloxacillin poisoning
- Intentional flucloxacillin overdose
- Intentional flucloxacillin poisoning
- Intentional penicillin G poisoning
- Intentional piperacillin poisoning
- Piperacillin poisoning
- Poisoning by ampicillin
- Poisoning by carbenicillin
- Poisoning by cloxacillin
- Poisoning by penicillin G
Coding GuidelinesGuidance
When coding a poisoning or reaction to the improper use of a medication (e.g., overdose, wrong substance given or taken in error, wrong route of administration), first assign the appropriate code from categories T36-T50. The poisoning codes have an associated intent as their 5th or 6th character (accidental, intentional self-harm, assault and undetermined). If the intent of the poisoning is unknown or unspecified, code the intent as accidental intent. The undetermined intent is only for use if the documentation in the record specifies that the intent cannot be determined. Use additional code(s) for all manifestations of poisonings.
The appropriate 7th character is to be added to each code from block Poisoning by, adverse effect of and underdosing of systemic antibiotics (T36). 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 2027, published by CMS and the National Center for Health Statistics.
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to T36.0X2A: its own notes plus those printed at T36, block T36-T50, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- adverse effect of correct substance properly administered
- poisoning by overdose of substance
- poisoning by wrong substance given or taken in error
- underdosing by (inadvertently) (deliberately) taking less substance than prescribed or instructed
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- toxic reaction to local anesthesia in pregnancy (O29.3-)
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
Code First
The underlying condition named in the note is sequenced before this code.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify any retained foreign body, if applicable (Z18.-)
Notes
General instructions on how these codes are used.
- Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
- The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.
7th Character
Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.
- The appropriate 7th character is to be added to each code from category T36
- Ainitial encounter this code
- Dsubsequent encounter
- Ssequela
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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
Antibiotics
Antibiotics are medicines that fight bacterial infections in people and animals. They work by killing the bacteria or by making it hard for the bacteria to grow and multiply.
The full article covers:
- What are antibiotics?
- What do antibiotics treat?
- Do antibiotics treat viral infections?
- What are the side effects of antibiotics?
- Why is it important to take antibiotics only when they're needed?
- How do I use antibiotics correctly?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert T36.0X2A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T36.0X2AOverview
What is the ICD-10 code for poisoning by penicillins, intentional self-harm, initial encounter?
The ICD-10-CM code for poisoning by penicillins, intentional self-harm, initial encounter is T36.0X2A (sometimes written as T360X2A). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is T36.0X2A (Poisoning by penicillins, intentional self-harm) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by penicillins, intentional self-harm, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What does the 7th character A in T36.0X2A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for poisoning by penicillins, intentional self-harm, such as an emergency visit or first evaluation.
What MS-DRG does T36.0X2A group to?
When poisoning by penicillins, intentional self-harm, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 918, 917, with relative weights from 0.8716 to 1.5698 depending on complications. Higher weights mean higher Medicare reimbursement.
Can T36.0X2A be reported with a code from T45.1?
Not as a rule. The Excludes1 note at T36, which applies to T36.0X2A, lists "antineoplastic antibiotics (T45.1-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What HCC is T36.0X2A?
T36.0X2A (poisoning by penicillins, intentional self-harm, initial encounter) maps to CMS-HCC Category 155 (Major Depression, Moderate or Severe, without Psychosis), commonly written as HCC 155, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 59 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 132.
Does T36.0X2A risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, T36.0X2A adds a risk adjustment factor of about 0.299 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.108 to 0.316 depending on the payment segment). A more severe related category (HCC 151, HCC 152, HCC 153, and HCC 154) supersedes it when both are reported. See the full factor table on the HCC 155 category page.
