ICD-10-CM 2027
ICD-10 code for tonsillitis
From the official ICD-10-CM alphabetic index entry “Tonsillitis (acute) (catarrhal) (croupous) (follicular) (gangrenous) (infective) (lacunar) (lingual) (malignant) (membranous) (parenchymatous) (phlegmonous) (pseudomembranous) (purulent) (septic) (subacute) (suppurative) (toxic) (ulcerative) (vesicular) (viral)”. Page updated September 29, 2026.
About coding tonsillitis
The ICD-10-CM code for tonsillitis is J03.90 (Acute tonsillitis, unspecified). The official index lists 14 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on J03.90.
Within J03.9, choose J03.90 (tonsillitis, unspecified) only when documentation doesn't support a more specific option: recurrent tonsillitis, unspecified (J03.91).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC, relative weight 5.6154), DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC, relative weight 4.381), DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC, relative weight 2.7307), DRG 152 (Otitis Media and URI with MCC, relative weight 1.1151) and DRG 153 (Otitis Media and URI without MCC, relative weight 0.7421), in Pre-MDC and MDC 03 (Diseases and Disorders of the Ear, Nose, Mouth and Throat), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific tonsillitis codes (official index)
- chronic J35.01 — Chronic tonsillitis
- with adenoiditis J35.03 — Chronic tonsillitis and adenoiditis
- diphtheritic A36.0 — Pharyngeal diphtheria
- hypertrophic J35.01 — Chronic tonsillitis
- with adenoiditis J35.03 — Chronic tonsillitis and adenoiditis
- recurrent J03.91 — Acute recurrent tonsillitis, unspecified
- specified organism NEC J03.80 — Acute tonsillitis due to other specified organisms
- recurrent J03.81 — Acute recurrent tonsillitis due to other specified organisms
- staphylococcal J03.80 — Acute tonsillitis due to other specified organisms
- recurrent J03.81 — Acute recurrent tonsillitis due to other specified organisms
- streptococcal J03.00 — Acute streptococcal tonsillitis, unspecified
- recurrent J03.01 — Acute recurrent streptococcal tonsillitis
- tuberculous A15.8 — Other respiratory tuberculosis
- Vincent's A69.1 — Other Vincent's infections
Common questions about tonsillitis ICD-10 codes
What is the ICD-10 code for tonsillitis?
- J03.90 — Acute tonsillitis, unspecified. More specific codes apply when the documentation supports them: J35.01, J35.03, A36.0, J35.01 and others below.
What is the ICD-10 code for chronic tonsillitis?
- J35.01 — Chronic tonsillitis.
What is the ICD-10 code for diphtheritic tonsillitis?
- A36.0 — Pharyngeal diphtheria.
What is the ICD-10 code for hypertrophic tonsillitis?
- J35.01 — Chronic tonsillitis.
What is the ICD-10 code for recurrent tonsillitis?
- J03.91 — Acute recurrent tonsillitis, unspecified.
What is the ICD-10 code for staphylococcal tonsillitis?
- J03.80 — Acute tonsillitis due to other specified organisms.
What is the ICD-10 code for streptococcal tonsillitis?
- J03.00 — Acute streptococcal tonsillitis, unspecified.
Is J03.90 billable?
- Yes. J03.90 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can J03.90 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict J03.90 as a principal diagnosis.
Is J03.90 a CC or MCC?
- No. J03.90 is neither a CC nor an MCC under MS-DRG v44.0.