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Z20.01 ICD-10-CM Code: Contact with and (suspected) exposure to intestinal infectious diseases due to Escherichia coli (E. coli)

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
2 Excludes1 · 1 Excludes2

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 795 — NORMAL NEWBORN (MDC 15)
  • MS-DRG 951 — OTHER FACTORS INFLUENCING HEALTH STATUS (MDC 23)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for Z20.01 in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on Z20.01 itself; “inherited from” names the category or block whose note applies here.

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from Z20

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Source: inherited from Z20

Coder workflow for Z20.01

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

Before you code Z20.01

  1. Z20.01’s title joins a condition with an associated condition or complication. Confirm each component is documented. Where the classification presumes the link through the “with” convention, only a provider statement that the conditions are unrelated defeats it. A combination code is assigned only when it fully identifies the documented conditions; a required second code for the stage, type or manifestation is still reported when the notes ask for it (Guidelines I.B.9, I.A.15).

    Guide: Combination codes →

  2. Confirm the reason for the encounter this Z code records: the circumstance it records. Check whether the code may be reported as first-listed or principal — some Z codes are limited to one position — and do not report a history or status code for a condition documented as current. Z code categories and their reporting positions (Guidelines I.C.21.c, I.C.21.c.15).

    Guide: Z codes as principal or first-listed diagnosis →

  3. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with Z20.01. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the documentation support a condition named in Z20.01’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewZ22

Consider Z20.01. Then 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).
The associated condition or complication
Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).
The reason for the encounter
Whether the code records the encounter’s purpose, a status, or a history — and whether it may be first-listed (Guidelines I.C.21.c).

Official instructions as workflow

  • Excludes1 — check before selecting Z20.01(2 notes)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with Z20.01: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareZ22

    See the official tabular notes · Guidelines I.A.12.a

  • Excludes2 — not part of Z20.01(1 note)

    Coding workflow: The conditions named in this note are not included in Z20.01. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareZ86.1

    See the official tabular notes · Guidelines I.A.12.b

Coding decision scenarios

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

Documentation: Both the condition Z20.01 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewZ22

Documentation: Only one of the components this code’s title joins is documented.

Coding question: Is Z20.01 supported?

Path: Review the code for the documented component on its own.

Reason: A combination code is assigned only when it fully identifies the documented conditions; otherwise the documented component takes its own code (Guidelines I.B.9).

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.

Code Overview

Contact with and (suspected) exposure to intestinal infectious diseases due to Escherichia coli (E. coli) is a billable ICD-10-CM diagnosis code (Z20.01).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (4)

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.

Official Coding Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Verbatim excerpts from the ICD-10-CM Official Guidelines for Coding and Reporting (CMS/NCHS) that govern this code.

Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99), U07.1, U09.9 a. Human Immunodeficiency Virus (HIV) Infections 1) Code only confirmed cases

For symptomatic individuals with actual or suspected exposure to COVID-19 and the infection has been ruled out, or test results are inconclusive or unknown, assign code Z20.822, Contact with and (suspected) exposure to COVID-19. See guideline I.C.21.c.1, Contact/Exposure, for additional guidance regarding the use of category Z20 codes.

Chapter 21: Factors influencing health status and contact with health services (Z00-Z99)

1) Contact/Exposure Category Z20 indicates contact with, and suspected exposure to, communicable diseases. These codes are for patients who are suspected to have been exposed to a disease by close personal contact with an infected individual or are in an area where a disease is epidemic.

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

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

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name Z20.01 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 2 Excludes2 notes: Z77 — Other contact with and (suspected) exposures hazardous to health (via Z20.-), Z83 — Family history of other specific disorders (via Z20.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

Not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity.

Named in the grouper logic of 2 MS-DRGs: DRG 795 (MDC 15), DRG 951 (MDC 23).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):FAC016 — Exposure, encounters, screening or contact with infectious disease (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Exposure, encounters, screening or contact with infectious disease).

Z11.2 — Encounter for screening for other bacterial diseases, Z11.3 — Encounter for screening for infections with a predominantly sexual mode of transmission, Z11.4 — Encounter for screening for human immunodeficiency virus [HIV], Z11.51 — Encounter for screening for human papillomavirus (HPV), Z11.52 — Encounter for screening for COVID-19, Z11.59 — Encounter for screening for other viral diseases, Z11.6 — Encounter for screening for other protozoal diseases and helminthiases, Z11.7 — Encounter for testing for latent tuberculosis infection, Z11.8 — Encounter for screening for other infectious and parasitic diseases, Z11.9 — Encounter for screening for infectious and parasitic diseases, unspecified, Z20.09 — Contact with and (suspected) exposure to other intestinal infectious diseases, Z20.1 — Contact with and (suspected) exposure to tuberculosis, Z20.2 — Contact with and (suspected) exposure to infections with a predominantly sexual mode of transmission, Z20.3 — Contact with and (suspected) exposure to rabies, Z20.4 — Contact with and (suspected) exposure to rubella, Z20.5 — Contact with and (suspected) exposure to viral hepatitis, Z20.6 — Contact with and (suspected) exposure to human immunodeficiency virus [HIV], Z20.7 — Contact with and (suspected) exposure to pediculosis, acariasis and other infestations, Z20.810 — Contact with and (suspected) exposure to anthrax, Z20.811 — Contact with and (suspected) exposure to meningococcus, +15 more

Same Index main term, other category

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

P00.82 — Newborn affected by (positive) maternal group B streptococcus (GBS) colonization (positive maternal group B streptococcus), P96.81 — Exposure to (parental) (environmental) tobacco smoke in the perinatal period (second hand tobacco smoke, in the perinatal period), T69.8 — Other specified effects of reduced temperature (cold, effects of, specified effect NEC), T69.9 — Effect of reduced temperature, unspecified (cold, effects of), T73.2 — Exhaustion due to exposure (exhaustion due to), T73.9 — Effect of deprivation, unspecified (effects of), T75.89 — Other specified effects of external causes, Z57.0 — Occupational exposure to noise (occupational, noise), Z57.1 — Occupational exposure to radiation (occupational, radiation), Z57.2 — Occupational exposure to dust (occupational, dust), Z57.31 — Occupational exposure to environmental tobacco smoke (occupational, environmental tobacco smoke), Z57.39 — Occupational exposure to other air contaminants (occupational, air contaminants NEC), Z57.4 — Occupational exposure to toxic agents in agriculture (occupational, toxic agentsin agriculture), Z57.5 — Occupational exposure to toxic agents in other industries (occupational, toxic agentsin industry NEC), Z57.6 — Occupational exposure to extreme temperature (occupational, extreme temperature), Z57.7 — Occupational exposure to vibration (occupational, vibration), Z57.8 — Occupational exposure to other risk factors (occupational, risk factors, specified NEC), Z57.9 — Occupational exposure to unspecified risk factor (occupational, risk factors), Z60.5 — Target of (perceived) adverse discrimination and persecution (persecution), Z65.4 — Victim of crime and terrorism (torture), +33 more

Contextual Map

Every relationship of Z20.01 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.

Run Z20.01 with these 2 related codes in Claim Check

Hierarchy

Referenced by Excludes2 notes

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

Index entries

  • Contact (with), Escherichia coli (E. coli)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Contact (with), intestinal infectious disease NEC, Escherichia coli (E. coli)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Exposure (to), Escherichia coli (E. coli)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Exposure (to), intestinal infectious disease NEC, Escherichia coli (E. coli)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (22)

Change history

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

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
Coding guidelines Official source data
ICD-10-CM Official Guidelines for Coding and Reporting (FY2026), quoted by section 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
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 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

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Contact with and (suspected) exposure to intestinal infectious diseases due to Escherichia coli (E. coli)

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to Z20.01 in its code family, with their registry titles.

View all codes in the Z20 family