Z12.11: Encounter for screening for malignant neoplasm of colon

The ICD-10-CM code for a colorectal cancer screening encounter when the patient is asymptomatic, carries no prior colorectal cancer diagnosis and is not under diagnostic workup for a gastrointestinal complaint.

Billable

FY2027

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At a glance

Code Family

Z12: Encounter for screening for malignant neoplasms.

Condition

Colorectal cancer screening

Billable

Yes, valid for HIPAA covered transactions.

HCC Mapping (v28)

None. Z12.11 does not map to a CMS-HCC payment category under v28. It did not map under v24.

Effective Date

Valid in the FY2026 code set and unchanged in the FY2027 update.

Family Specificity

Subcategory Z12.1 splits by the segment of the intestinal tract that is screened. Z12.11 is the colon entry and the code paired with a screening colonoscopy.

Which Z12 code do I assign?

The screening codes split first on intent and only then on anatomy. Establish that the encounter is screening rather than diagnostic or surveillance, then match the child code to the segment the note names.

When documentation says…

Code

Asymptomatic patient presenting for routine colorectal cancer screening

Z12.11

Screening of the colon in a patient with no current symptoms, no prior colorectal cancer diagnosis and no active diagnostic workup. The note must record the encounter as screening and the patient as asymptomatic.

Screening limited to the rectum

Z12.12

Screening for malignant neoplasm of the rectum. Assign this code when the screening is rectal in scope rather than an examination of the colon.

Screening for intestinal cancer, site not documented

Z12.10

Screening of the intestinal tract with the anatomic site unspecified. Assign this code only when the record does not name the segment screened.

Small bowel screening ordered

Z12.13

Screening for malignant neoplasm of the small intestine. The note must document screening intent directed at the small bowel specifically.

Colonoscopy ordered to investigate rectal bleeding or abdominal pain

K62.5

The encounter is diagnostic rather than screening. The Excludes1 note at category Z12 directs an encounter for diagnostic examination to the sign or symptom. Code the documented sign or symptom, such as K62.5, Hemorrhage of anus and rectum, which the Index gives for rectal bleeding.

Surveillance colonoscopy after prior polyp removal

Z86.010-

Personal history of colon polyps, subdivided by polyp type. Post polypectomy surveillance is a follow up encounter rather than a screening encounter. Z12.11 does not apply. Category Z86 carries a Code first note for any follow-up examination after treatment (Z09).

Prior colon or rectal cancer, returning for surveillance

Z85.038

Personal history of other malignant neoplasm of large intestine. A patient whose colorectal cancer treatment is complete is under surveillance rather than screening. Z08 is sequenced first, followed by the history code (Guideline I.C.21.c.8). A prior colon cancer takes Z85.038. A prior rectal cancer takes Z85.048, personal history of other malignant neoplasm of rectum, rectosigmoid junction, and anus.

Tabular notes

EXCLUDES1

Category Z12 carries an Excludes1 note: encounter for diagnostic examination, code to sign or symptom. The note sits at the category and governs Z12.11 and every other Z12 code. Where the patient presents with a sign or symptom such as hematochezia or abdominal pain, the encounter is diagnostic. Assign the sign or symptom code in place of Z12.11. A condition discovered during the screening is different: Section I.C.21.c.5 allows its code as an additional diagnosis. Z12.11, Z12.1 and Z12 carry no Excludes2 note in the FY2027 tabular. Block Z00-Z13 carries an Excludes2 note for examinations related to pregnancy and reproduction (the Z30-Z36 and Z39 codes).

USE ADDITIONAL

Category Z12 carries a Use additional note to identify any family history of malignant neoplasm (Z80.-), which applies to Z12.11. Where a family history of colorectal cancer is documented as a reason for the screening, add the applicable code from that family. Z80.0, family history of malignant neoplasm of digestive organs, is the entry for colorectal cancer.

FY2027: EFFECTIVE 1 OCTOBER 2026

The FY2027 codes addenda make no addition, deletion or revision in category Z12. The FY2027 tabular addenda change no instructional note in it. The code description, the Excludes1 note and the Use Additional instruction are unchanged. Z12.11 is in the FY2027 billable code list and is unchanged in the FY2027 update.

Operational & financial impact

Why specificity matters beyond the chart: risk adjustment, DRG assignment and denial exposure all follow from which code is selected.

CMS-HCC v28 (PY2024+)

None. Z12.11 does not map to any HCC category under CMS-HCC v28 and contributes no RAF.

Z-codes in the screening block carry no risk adjustment value. The financial weight of a Z12.11 encounter rests on the preventive benefit rules rather than on the risk score.

V24 TO V28 TRANSITION

Z12.11 carried no HCC mapping under CMS-HCC v24. Its risk adjustment status is unchanged under v28.

MS-DRG v44 (FY2027)

Z12.11 is a preventive screening code used in outpatient and ambulatory settings. Screening colonoscopy is performed in an outpatient environment.

As a principal inpatient diagnosis, Z12.11 groups to MS-DRG 951, Other Factors Influencing Health Status, in MDC 23 under the FY2027 MS-DRG v44 grouper.

MEDICARE AND COMMERCIAL PAYERS

Medicare covers colorectal cancer screening under Part B as a preventive benefit. The HCPCS procedure codes for screening colonoscopy are G0105 for a high risk beneficiary and G0121 for an average risk beneficiary. Z12.11 is the diagnosis code paired with those HCPCS codes on Medicare claims.

Preventive colonoscopy under Medicare carries no patient cost sharing, with no deductible and no coinsurance, when it is performed as a screening service. That status may be affected when the service converts to a diagnostic procedure during the session.

Modifier PT, colorectal cancer screening test converted to diagnostic test or other procedure, is a Medicare modifier. It is appended to the therapeutic CPT code when a scheduled screening colonoscopy converts during the same session. It preserves the applicable cost sharing benefit for the beneficiary. Cost sharing on the converted procedure may differ. Do not submit modifier PT to a commercial payer.

Modifier 33, preventive service, is an AMA CPT modifier for ACA-compliant commercial plans. It signals that the procedure meets a USPSTF Grade A or Grade B recommendation. It triggers first dollar coverage with no patient cost sharing. CMS does not recognize modifier 33, and submitting it on a Medicare claim generates a claims processing error. Apply each modifier strictly to its own payer type.

The USPSTF final recommendation of 18 May 2021 grades colorectal cancer screening A for ages 50 to 75 and B for ages 45 to 49. Grade A and Grade B recommendations mandate first dollar coverage under ACA-compliant commercial plans. For ages 76 to 85 the USPSTF records small net benefit for the previously screened, and individual clinical judgment applies.

No National Coverage Determination specific to Z12.11 coding exists. Coverage is governed by the CMS preventive benefit statutes at Section 1861 of the Social Security Act, by the ACA for commercial plans, and by the applicable Local Coverage Determinations from the relevant MAC.

WHERE SPECIFICITY IS LOST

Reporting Z12.10, intestinal tract site unspecified, when the record names the colon discards the anatomic specificity that Z12.11 provides.

Assigning Z12.11 to a surveillance encounter misstates the intent of the visit. The personal history codes, the Z86.010 codes, Z85.038 and Z85.048, carry the surveillance context that determines whether the beneficiary is screened as high risk or average risk.

Omitting the Z80.- family history code when a family history of colorectal cancer is documented drops the indication that the Use Additional instruction requires.

Documentation checklist to support Z12.11

Chart elements that support code selection and reduce specificity-driven denials.

A statement that the patient is asymptomatic at the time of the encounter.

The screening purpose of the visit recorded as the reason for the encounter.

The anatomic scope of the screening, distinguishing an examination of the colon from a rectal or small bowel examination.

The absence of a prior colorectal cancer diagnosis, which would make the encounter surveillance rather than screening.

Any prior polyp removal, which directs the encounter to the personal history codes rather than to Z12.11.

Family history of colorectal cancer where it is documented as a reason for screening, in enough detail to assign the Z80.- code that the Use Additional instruction requires.

The patient age, which determines whether the USPSTF Grade A or Grade B recommendation applies to the encounter.

Any finding identified during the examination, such as a colon polyp, in enough detail to assign the finding code alongside Z12.11.

The payer type, which determines whether modifier PT or modifier 33 applies when a screening colonoscopy converts to a diagnostic or therapeutic procedure.

FAQ

Is Z12.11 billable?

Yes. Z12.11 is a valid billable code for HIPAA covered transactions. It is a complete code and takes no further character.

Can I use Z12.11 if the patient has rectal bleeding?

No. Category Z12 carries an Excludes1 note that governs Z12.11: encounter for diagnostic examination, code to sign or symptom. Rectal bleeding is a sign. The encounter is diagnostic rather than screening. Assign the applicable sign or symptom code, such as K62.5 for rectal bleeding, in place of Z12.11.

What code applies to a surveillance colonoscopy after a prior polyp or a prior colorectal cancer?

Surveillance is not screening. For a patient returning after polyp removal, a code from subcategory Z86.010, personal history of colon polyps, carries the history. Category Z86 carries a Code first note for any follow-up examination after treatment (Z09). For a patient whose colorectal cancer treatment is complete, Z08 is sequenced first, followed by the history code (Guideline I.C.21.c.8). A prior colon cancer takes Z85.038, personal history of other malignant neoplasm of large intestine. A prior rectal cancer takes Z85.048, personal history of other malignant neoplasm of rectum, rectosigmoid junction, and anus.

What do I code when a polyp is found during a screening colonoscopy?

Assign Z12.11 as the first listed code and the finding as an additional code, such as K63.5 for a polyp of the colon (Section I.C.21.c.5). The discovery of an incidental finding during a screening encounter does not retroactively change the intent of that encounter from screening to diagnostic.

Which modifier applies when a screening colonoscopy converts to a diagnostic or therapeutic procedure?

The answer follows the payer. Use modifier PT on a Medicare claim, appended to the therapeutic CPT code. Use modifier 33 on a claim to an ACA-compliant commercial plan. CMS does not recognize modifier 33, and a Medicare claim carrying it generates a claims processing error.

Does Z12.11 contribute to HCC risk adjustment?

No. Z12.11 is a preventive Z-code and maps to no CMS-HCC v28 or v24 payment category. It contributes no RAF and no risk score to a Medicare Advantage plan.

Is Z12.11 first listed, and does it work differently on an inpatient claim?

Section I.C.21.c.5 allows a screening code as the first listed code when the reason for the visit is specifically the screening exam. Z12.11 is first listed for an ambulatory screening colonoscopy where no concurrent acute condition overrides that reason. Outpatient coding does not permit possible or probable diagnoses, and Z12.11 is definitive in recording the reason for the encounter.

Did anything change for Z12.11 in FY2027?

No. Z12.11 is unchanged in the FY2027 update, effective 1 October 2026. The FY2027 addenda make no change in category Z12. The Excludes1 and Use Additional notes at Z12 are unchanged.

Related codes

Codes in the same family as Z12.11. Only codes with a published page render as links.

Sibling codes in the Z12 family

Z12.10: Encounter for screening for malignant neoplasm of intestinal tract, unspecified.
Z12.12: Encounter for screening for malignant neoplasm of rectum.
Z12.13: Encounter for screening for malignant neoplasm of small intestine.

Additional codes to consider

Codes outside the Z12 family considered alongside Z12.11.

Companion: code alongside when documented

Z80.0: Family history of malignant neoplasm of digestive organs, required by the Use Additional instruction when a family history of colorectal cancer is documented.
Z80.-: Family history of primary malignant neoplasm, where the documented family history is of another site.
K63.5: Polyp of colon, reported additionally when a polyp is found during the screening examination (Guideline I.C.21.c.5).

Consider instead

Z86.010-: Personal history of colon polyps, where the encounter is post polypectomy surveillance.
Z85.038: Personal history of other malignant neoplasm of large intestine, where the patient carries a prior colon cancer diagnosis.
Z85.048: Personal history of other malignant neoplasm of rectum, rectosigmoid junction, and anus, where the patient carries a prior rectal cancer diagnosis.
Z08: Encounter for follow-up examination after completed treatment for malignant neoplasm, for post treatment surveillance rather than initial screening.
K62.5: Hemorrhage of anus and rectum, one example of a code assigned in place of Z12.11 when the patient presents with rectal bleeding.

Sources

All claims on this page derive from government and professional-standards sources.

National Center for Health Statistics. (2026). International classification of diseases, tenth revision, clinical modification (ICD-10-CM) FY2027 files. https://www.cdc.gov/nchs/icd/icd-10-cm/files.html
Centers for Medicare & Medicaid Services and National Center for Health Statistics. (2026). ICD-10-CM official guidelines for coding and reporting FY2027. https://ftp.cdc.gov/pub/Health_Statistics/NCHS/Publications/ICD10CM/2027/ICD-10-CM-October-1-2026-FY27-Guidelines.pdf
Centers for Medicare & Medicaid Services. (2025). 2026 model software/ICD-10 mappings. https://www.cms.gov/medicare/payment/medicare-advantage-rates-statistics/risk-adjustment/2026-model-software-icd-10-mappings
Centers for Medicare & Medicaid Services. (2026). MS-DRG classifications and software, version 44. https://www.cms.gov/medicare/payment/prospective-payment-systems/acute-inpatient-pps/ms-drg-classifications-and-software