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T88.1XXA

T88.1XXAOther complications following immunization, not elsewhere classified, initial encounter

Billable / specific codeICD-10-CM

T88.1XXA is a billable, specific ICD-10-CM code for other complications following immunization, not elsewhere classified, initial encounter. It is valid for submission on a claim.

7th character "A" — initial encounter

The appropriate 7th character is to be added to each code from category T88

A
initial encounter
D
subsequent encounter
S
sequela

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

  • vaccinia not from vaccine (B08.011)

Excludes2 — not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

  • anaphylactic shock due to serum (T80.5-)
  • other serum reactions (T80.6-)
  • postimmunization arthropathy (M02.2)
  • postimmunization encephalitis (G04.02)
  • postimmunization fever (R50.83)

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Generalized vaccinia
  • Rash following immunization

Excludes1 inherited from the categories above T88.1XXA

These are not written on T88.1XXA, but they bind it: a note on a category applies to every code beneath it. Billing T88.1XXA with anything listed here is a denial.

Written on T88.1 Other complications following immunization, not elsewhere classified

  • vaccinia not from vaccine (B08.011)

Excludes2 inherited from the categories above T88.1XXA

Also inherited, and the opposite of Excludes1: these conditions are not part of T88.1XXA, but a patient can have both, so you may code both.

Written on T88.1 Other complications following immunization, not elsewhere classified

  • anaphylactic shock due to serum (T80.5-)
  • other serum reactions (T80.6-)
  • postimmunization arthropathy (M02.2)
  • postimmunization encephalitis (G04.02)
  • postimmunization fever (R50.83)

Written on T88 Other complications of surgical and medical care, not elsewhere classified

  • complication following infusion, transfusion and therapeutic injection (T80.-)
  • complication following procedure NEC (T81.-)
  • complications of anesthesia in labor and delivery (O74.-)
  • complications of anesthesia in pregnancy (O29.-)
  • complications of anesthesia in puerperium (O89.-)
  • complications of devices, implants and grafts (T82-T85)
  • complications of obstetric surgery and procedure (O75.4)
  • dermatitis due to drugs and medicaments (L23.3, L24.4, L25.1, L27.0-L27.1)
  • poisoning and toxic effects of drugs and chemicals (T36-T65 with fifth or sixth character 1-4)
  • specified complications classified elsewhere

Risk adjustment

T88.1XXA does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

T88.1XXA is named in 2 Medicare coverage policies 2 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A56559Billing and Coding: Allergy Skin Testing
  • A57206Billing and Coding: Lumbar MRI

Code history

T88.1XXA has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Related codes at this level

Codes that share T88.1. If T88.1XXA is not quite right, the correct code is usually one of these.

Questions about T88.1XXA

Is T88.1XXA a billable ICD-10-CM code?
Yes. T88.1XXA is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does T88.1XXA sit in the tabular list?
Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Complications of surgical and medical care, not elsewhere classified (T80-T88).
What cannot be coded together with T88.1XXA?
T88.1XXA carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above T88.1XXA (T88.1) and apply to it just the same.
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.