T70.1 ICD-10-CM Code: Sinus barotrauma

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for T70.1 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on T70.1 itself; “inherited from” names the category or block whose note applies here.

7th Character Guide

"The appropriate 7th character is to be added to each code from category T70"

• A — initial encounter
• D — subsequent encounter
• S — sequela

How the encounter character is assigned. “Initial encounter” means the patient is receiving active treatment for the condition — it is not limited to the first visit, and a different or new provider giving active treatment still assigns it. “Subsequent encounter” covers care during the healing or recovery phase after active treatment. “Sequela” is for complications or conditions that arise as a direct result of the original condition.

ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19.a (paraphrased by MedCoder).

Variant codes in this family

T70.1XXA, T70.1XXD, T70.1XXS

Character meanings are CMS's official 7th-character extensions for this family, as carried in each variant code's official description; variant codes are registry rows. The explanation of how the encounter character is assigned is MedCoder editorial, distinct from the official content above it.

Coder workflow for T70.1

MedCoder structured workflow — derived from this code’s own official record

Before you code T70.1

1. T70.1 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).

   ReviewT70.1XXA, T70.1XXD, T70.1XXS

   See the relationships section · Guide: How to choose an ICD-10-CM code →

2. A 7th character is required in this family. Confirm the documented encounter: initial (active treatment), subsequent (healing or recovery phase), or sequela. T70.1 is not valid without one. “Initial” means active treatment, not the first visit (Guidelines I.C.19.a).

   See the 7th Character Guide · Guide: 7th characters: initial, subsequent, sequela →

Choose the right path

1. Does the documentation support one of the more specific codes beneath T70.1?
   Yes → Select that code and continue the checks below on its own page.
   No → T70.1 cannot be reported as written; query for the specificity its subcategory needs.

   ReviewT70.1XXA, T70.1XXD, T70.1XXS

2. Is the encounter phase documented — active treatment, healing or recovery, or a sequela?
   Yes → Assign the matching 7th character; the variant codes are in the 7th Character Guide.
   No → The code is invalid without its 7th character — query for the missing element.

Consider T70.1. Then review the Code Also note, and confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement

Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).

Encounter type

Active treatment, healing or recovery phase, or sequela — the basis of the 7th character (Guidelines I.C.19.a).

Official instructions as workflow

• Code Also — related condition(6 notes)

  Coding workflow: Review the related condition when both are documented and the instruction applies. A Code Also note does not fix sequencing; the order follows the circumstances of the encounter.

  ReviewY92.523, Y92.21, Y92.52, Y92.01, Y92.81

  See the official tabular notes · Guidelines I.A.17

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Indexed Clinical Terms (6)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

• Aerosinusitis
• Barosinusitis
• Barotrauma, sinus
• Effect, adverse, high altitude NEC, on, sinuses
• High, altitude effects, on, sinuses
• Sinusitis (accessory) (chronic) (hyperplastic) (nasal) (nonpurulent) (purulent), due to high altitude

Don’t confuse T70.1 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of T70.1 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• T70.2— Specificity relationship (Review)

  Overlapping diagnoses in the same category.

  Overlapping codes in the same category — the documentation decides which is the more specific fit.

  What moves you there: A record that documents no more than “Other and unspecified effects of high altitude” takes T70.2; specificity in the record moves it back here.

  Full comparison: T70.1 vs T70.2 →

• T70.1XXA— Encounter relationship (Review)

  Same underlying diagnosis, different encounter phase.

  The same diagnosis at a different phase of care; one encounter takes one 7th character.

  What moves you there: Documentation of a initial encounter moves the case to T70.1XXA.

  Full comparison: T70.1 vs T70.1XXA →

• T70.1XXD— Encounter relationship (Review)

  Same underlying diagnosis, different encounter phase.

  The same diagnosis at a different phase of care; one encounter takes one 7th character.

  What moves you there: Documentation of a subsequent encounter moves the case to T70.1XXD.

  Full comparison: T70.1 vs T70.1XXD →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Verify Before Coding

• Not billable as written — a more specific code is required: T70.1XXA, T70.1XXD, T70.1XXS.
• Requires a 7th character. "The appropriate 7th character is to be added to each code from category T70" Options: T70.1XXA, T70.1XXD, T70.1XXS

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Related Codes

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Effect, adverse”, “High”; these codes share that main term but sit in a different category of the Tabular List.

Q76.6 — Other congenital malformations of ribs (thoracic rib), Q79.1 — Other congenital malformations of diaphragm (diaphragm), R03.0 — Elevated blood-pressure reading, without diagnosis of hypertension (blood pressure, borderline), R50.9 — Fever, unspecified (temperature), R94.8 — Abnormal results of function studies of other organs and systems (basal metabolic rate), T59.9 — Toxic effect of unspecified gases, fumes and vapors (gases, fumes, or vapors), T66 — Radiation sickness, unspecified (infrared NOS), T69.1 — Chilblains (cold, chilblains), T69.8 — Other specified effects of reduced temperature (cold, specified effect NEC), T69.9 — Effect of reduced temperature, unspecified (cold), T73.0 — Starvation (hunger), T73.1 — Deprivation of water (thirst), T73.3 — Exhaustion due to excessive exertion (exertion), T75.1 — Unspecified effects of drowning and nonfatal submersion (submersion), T75.3 — Motion sickness (motion), T75.4 — Electrocution (electric current, electricity), T75.81 — Effects of abnormal gravitation [G] forces (abnormal gravitationalforces or states), T75.82 — Effects of weightlessness (weightlessness), T75.838 — Effects of other war theater (war theater, specified NEC), T75.89 — Other specified effects of external causes (external cause NEC), +64 more

Contextual Map

Every relationship of T70.1 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Hierarchy

• S00-T88 — Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) (S00-T88)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T66-T78 — Other and unspecified effects of external causes[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Index entries

• Aerosinusitis[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Barosinusitis[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Barotrauma, sinus[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Effect, adverse, high altitude NEC, on, sinuses[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• High, altitude effects, on, sinuses[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Sinusitis (accessory) (chronic) (hyperplastic) (nasal) (nonpurulent) (purulent), due to high altitude[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (33)

• T70 — Effects of air pressure and water pressure[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T70.0 — Otitic barotrauma[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T70.0XXA — Otitic barotrauma, initial encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T70.0XXD — Otitic barotrauma, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T70.0XXS — Otitic barotrauma, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T70.1XXA — Sinus barotrauma, initial encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T70.1XXD — Sinus barotrauma, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T70.1XXS — Sinus barotrauma, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 25 more

Change history

• FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Common coding questions

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data

CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page

Change history and date-of-service validity Official source data

CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page

Comparisons, relationships and the contextual map MedCoder structured relationship

Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears

Summary and FAQ answers MedCoder explanation

Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T70.1 in its code family, with their registry titles.

• T70 — Effects of air pressure and water pressure
• T70.0 — Otitic barotrauma
• T70.0XXA — Otitic barotrauma, initial encounter
• T70.0XXD — Otitic barotrauma, subsequent encounter
• T70.0XXS — Otitic barotrauma, sequela
• T70.1XXA — Sinus barotrauma, initial encounter
• T70.1XXD — Sinus barotrauma, subsequent encounter
• T70.1XXS — Sinus barotrauma, sequela
• T70.2 — Other and unspecified effects of high altitude
• T70.20 — Unspecified effects of high altitude

View all codes in the T70 family