2027 ICD-10-CM Diagnosis Code T45.1X2APoisoning by antineoplastic and immunosuppressive drugs, intentional self-harm, initial encounter
T45.1X2A is a billable ICD-10-CM diagnosis code for poisoning by antineoplastic and immunosuppressive drugs, 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, T45.1X2A 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
T45.1X2A 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.
- Aclarubicin overdose
- Aclarubicin poisoning
- Aminoglutethimide overdose
- Aminoglutethimide poisoning
- Amsacrine overdose
- Amsacrine poisoning
- Azathioprine overdose
- Bleomycin overdose
- Busulfan overdose
- Calcineurin inhibitor poisoning
- Carbamate overdose
- Carboplatin overdose
- Carboplatin poisoning
- Carmustine overdose
- Carmustine poisoning
- Chlorambucil overdose
- Chlormethine overdose
- Chlormethine poisoning
- Cisplatin overdose
- Cisplatin poisoning
- Crisantaspase overdose
- Crisantaspase poisoning
- Cyclophosphamide overdose
- Cyclosporin overdose
- Cyclosporin poisoning
- Cytarabine overdose
- Dacarbazine overdose
- Dacarbazine poisoning
- Dactinomycin overdose
- Doxorubicin overdose
- Doxorubicin poisoning
- Enzyme overdose
- Epirubicin overdose
- Epirubicin poisoning
- Estramustine overdose
- Estramustine poisoning
- Ethoglucid overdose
- Ethoglucid poisoning
- Etoposide overdose
- Etoposide poisoning
- Fludarabine overdose
- Fludarabine poisoning
- Fluorouracil overdose
- Hydroxycarbamide overdose
- Hydroxycarbamide poisoning
- Idarubicin overdose
- Idarubicin poisoning
- Ifosfamide overdose
- Ifosfamide poisoning
- Intentional aclarubicin overdose
- Intentional aclarubicin poisoning
- Intentional aminoglutethimide overdose
- Intentional aminoglutethimide poisoning
- Intentional amsacrine overdose
- Intentional amsacrine poisoning
- Intentional azathioprine overdose
- Intentional azathioprine poisoning
- Intentional bleomycin overdose
- Intentional bleomycin poisoning
- Intentional busulfan overdose
- Intentional busulfan poisoning
- Intentional carboplatin overdose
- Intentional carboplatin poisoning
- Intentional carmustine overdose
- Intentional carmustine poisoning
- Intentional chlorambucil overdose
- Intentional chlorambucil poisoning
- Intentional chlormethine overdose
- Intentional chlormethine poisoning
- Intentional cisplatin overdose
- Intentional cisplatin poisoning
- Intentional crisantaspase overdose
- Intentional crisantaspase poisoning
- Intentional cyclophosphamide overdose
- Intentional cyclophosphamide poisoning
- Intentional cyclosporin overdose
- Intentional cyclosporin poisoning
- Intentional cytarabine overdose
- Intentional cytarabine poisoning
- Intentional dacarbazine overdose
- Intentional dacarbazine poisoning
- Intentional dactinomycin overdose
- Intentional dactinomycin poisoning
- Intentional daunorubicin poisoning
- Intentional doxorubicin overdose
- Intentional doxorubicin poisoning
- Intentional epirubicin overdose
- Intentional epirubicin poisoning
- Intentional estramustine overdose
- Intentional estramustine poisoning
- Intentional ethoglucid overdose
- Intentional ethoglucid poisoning
- Intentional etoposide overdose
- Intentional etoposide poisoning
- Intentional fludarabine overdose
- Intentional fludarabine poisoning
- Intentional fluorouracil overdose
- Intentional fluorouracil poisoning
- Intentional hydroxycarbamide overdose
- Intentional hydroxycarbamide poisoning
- Intentional idarubicin overdose
- Intentional idarubicin poisoning
- Intentional ifosfamide overdose
- Intentional ifosfamide poisoning
- Intentional lomustine overdose
- Intentional lomustine poisoning
- Intentional melphalan overdose
- Intentional melphalan poisoning
- Intentional mercaptopurine overdose
- Intentional mercaptopurine poisoning
- Intentional methotrexate overdose
- Intentional methotrexate poisoning
- Intentional mitobronitol overdose
- Intentional mitobronitol poisoning
- Intentional mitomycin overdose
- Intentional mitomycin poisoning
- Intentional mitoxantrone overdose
- Intentional mitoxantrone poisoning
- Intentional paclitaxel overdose
- Intentional paclitaxel poisoning
- Intentional pentostatin overdose
- Intentional pentostatin poisoning
- Intentional plicamycin overdose
- Intentional plicamycin poisoning
- Intentional procarbazine overdose
- Intentional procarbazine poisoning
- Intentional razoxane overdose
- Intentional razoxane poisoning
- Intentional thioguanine overdose
- Intentional thioguanine poisoning
- Intentional thiotepa overdose
- Intentional thio-TEPA poisoning
- Intentional treosulfan overdose
- Intentional treosulfan poisoning
- Intentional vinblastine overdose
- Intentional vinblastine poisoning
- Intentional vincristine overdose
- Intentional vincristine poisoning
- Intentional vindesine overdose
- Intentional vindesine poisoning
- Lomustine overdose
- Lomustine poisoning
- Melphalan overdose
- Melphalan poisoning
- Mercaptopurine overdose
- Methotrexate overdose
- Methotrexate poisoning
- Mitobronitol overdose
- Mitobronitol poisoning
- Mitomycin overdose
- Mitoxantrone overdose
- Mitoxantrone poisoning
- Nitrosurea overdose
- Paclitaxel overdose
- Paclitaxel poisoning
- Pentostatin overdose
- Pentostatin poisoning
- Plicamycin overdose
- Plicamycin poisoning
- Poisoning by actinomycin
- Poisoning by azathioprine
- Poisoning by bleomycin
- Poisoning by busulfan
- Poisoning by chlorambucil
- Poisoning by cyclophosphamide
- Poisoning by cytarabine
- Poisoning by daunorubicin
- Poisoning by fluorouracil
- Poisoning by L-asparaginase
- Poisoning by mercaptopurine
- Poisoning by mitomycin
- Poisoning by thiotepa
- Procarbazine overdose
- Procarbazine poisoning
- Razoxane overdose
- Razoxane poisoning
- Thioguanine overdose
- Thioguanine poisoning
- Thiotepa overdose
- Treosulfan overdose
- Treosulfan poisoning
- Triazene antineoplastic overdose
- Vinblastine overdose
- Vinblastine poisoning
- Vinca alkaloid overdose
- Vincristine overdose
- Vincristine poisoning
- Vindesine overdose
- Vindesine poisoning
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 primarily systemic and hematological agents, not elsewhere classified (T45). 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 T45.1X2A: its own notes plus those printed at T45.1, T45, 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 T45
- Ainitial encounter this code
- Dsubsequent encounter
- Ssequela
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name T45.1X2A, its category, or a range that includes it.
Excludes1 3
These codes carry an Excludes1 note naming T45.1X2A: they are not reported together with it, unless the two conditions are unrelated.
- T36 Poisoning by, adverse effect of and underdosing of systemic antibioticsantineoplastic antibiotics (T45.1-) names T45.1-, which includes this code
- T37.5 Poisoning by, adverse effect of and underdosing of antiviral drugscytarabine (T45.1-) names T45.1-, which includes this code
- T45.A Poisoning by, adverse effect of and underdosing of immune checkpoint inhibitors and immunostimulant drugspoisoning by, adverse effect of and underdosing of antineoplastic and immunosuppressive drug (T45.1) names T45.1, which includes this code
Code Also 3
These codes say T45.1X2A may also be needed to fully describe the condition. The note gives no sequencing direction.
- J34.81 Nasal mucositis (ulcerative)antineoplastic and immunosuppressive drugs (T45.1X-) names T45.1X-, which includes this code
- K92.81 Gastrointestinal mucositis (ulcerative)antineoplastic and immunosuppressive drugs (T45.1X-) names T45.1X-, which includes this code
- N76.81 Mucositis (ulcerative) of vagina and vulvaantineoplastic and immunosuppressive drugs (T45.1X-) names T45.1X-, which includes this code
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
Poisoning
A poison is any substance that is harmful to your body. You might swallow it, inhale it, inject it, or absorb it through your skin. Any substance can be poisonous if too much is taken. Poisons can include:
Read the full article at MedlinePlus
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Convert T45.1X2A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T45.1X2AOverview
Is T45.1X2A a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by antineoplastic and immunosuppressive drugs, intentional self-harm, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What does the 7th character A in T45.1X2A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for poisoning by antineoplastic and immunosuppressive drugs, intentional self-harm, such as an emergency visit or first evaluation.
What MS-DRG does T45.1X2A group to?
When poisoning by antineoplastic and immunosuppressive drugs, 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 T45.1X2A be reported with T45.A?
Not as a rule. The Excludes1 note at T45.1, which applies to T45.1X2A, lists "poisoning by, adverse effect of and underdosing of immune checkpoint inhibitors and immunostimulant drugs (T45.A)". 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 is the ICD-9 equivalent of T45.1X2A?
Under the General Equivalence Mappings, poisoning by antineoplastic and immunosuppressive drugs, intentional self-harm, initial encounter converts to ICD-9-CM 963.1 (pois-antineopl/immunosup) and E950.4 (poison-drug/medicin NEC). The mapping is approximate, so confirm the match fits the documentation.
What HCC is T45.1X2A?
T45.1X2A (poisoning by antineoplastic and immunosuppressive drugs, 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 T45.1X2A risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, T45.1X2A 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.
