Q45.1 ICD-10-CM Code: Annular pancreas

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for Q45.1 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 Q45.1 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for Q45.1

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

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).

Official instructions as workflow

• Excludes2 — not part of Q45.1(2 notes)

  Coding workflow: The conditions named in this note are not included in Q45.1. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareQ79.0, Q40.1

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

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 (1)

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.

• Annular, pancreas (congenital)

Don’t confuse Q45.1 with…

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

The codes most likely to be picked instead of Q45.1 — 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.

• Q45.9— 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 “Congenital malformation of digestive system, unspecified” takes Q45.9; specificity in the record moves it back here.

  Full comparison: Q45.1 vs Q45.9 →

• Q79.0— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of congenital diaphragmatic hernia adds Q79.0; it is not part of this code and both may be reported when both are documented.

  Full comparison: Q45.1 vs Q79.0 →

• Q40.1— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of congenital hiatus hernia adds Q40.1; it is not part of this code and both may be reported when both are documented.

  Full comparison: Q45.1 vs Q40.1 →

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

• CC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.

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

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 6 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 3 MS-DRGs: DRG 438 (MDC 07), DRG 439 (MDC 07), DRG 440 (MDC 07).

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

Clinical classification (AHRQ CCSR):MAL002 — Digestive congenital anomalies (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 process (MS-DRG)

Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

Q45.0 — Agenesis, aplasia and hypoplasia of pancreas, Q45.2 — Congenital pancreatic cyst, Q45.3 — Other congenital malformations of pancreas and pancreatic duct, Q45.8 — Other specified congenital malformations of digestive system, Q45.9 — Congenital malformation of digestive system, unspecified

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Digestive congenital anomalies).

Q43.6 — Congenital fistula of rectum and anus, Q43.7 — Persistent cloaca, Q43.8 — Other specified congenital malformations of intestine, Q43.9 — Congenital malformation of intestine, unspecified, Q44.0 — Agenesis, aplasia and hypoplasia of gallbladder, Q44.1 — Other congenital malformations of gallbladder, Q44.2 — Atresia of bile ducts, Q44.3 — Congenital stenosis and stricture of bile ducts, Q44.4 — Choledochal cyst, Q44.5 — Other congenital malformations of bile ducts, Q44.6 — Cystic disease of liver, Q44.7 — Other congenital malformations of liver, Q44.70 — Other congenital malformation of liver, unspecified, Q44.71 — Alagille syndrome, Q44.79 — Other congenital malformations of liver, Q45.0 — Agenesis, aplasia and hypoplasia of pancreas, Q45.2 — Congenital pancreatic cyst, Q45.3 — Other congenital malformations of pancreas and pancreatic duct, Q45.8 — Other specified congenital malformations of digestive system, Q45.9 — Congenital malformation of digestive system, unspecified, +41 more

Same Index main term, other category

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

N88.8 — Other specified noninflammatory disorders of cervix uteri

Contextual Map

Every relationship of Q45.1 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

• Q00-QA1 — Chapter 17: Congenital Malformations, Deformations and Chromosomal Abnormalities (Q00-QA1) (Q00-QA1)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• Q38-Q45 — Other congenital malformations of the digestive system[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Clinical classification (CCSR)

• MAL002 — Digestive congenital anomalies[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

MS-DRG Grouper

• CC — Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (CC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2026
• DRG 438 — DISORDERS OF PANCREAS EXCEPT MALIGNANCY WITH MCC[MS-DRG]: “DISORDERS OF PANCREAS EXCEPT MALIGNANCY WITH MCC (MDC 07)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 439 — DISORDERS OF PANCREAS EXCEPT MALIGNANCY WITH CC[MS-DRG]: “DISORDERS OF PANCREAS EXCEPT MALIGNANCY WITH CC (MDC 07)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 440 — DISORDERS OF PANCREAS EXCEPT MALIGNANCY WITHOUT CC/MCC[MS-DRG]: “DISORDERS OF PANCREAS EXCEPT MALIGNANCY WITHOUT CC/MCC (MDC 07)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 07 — Diseases and Disorders of the Hepatobiliary System and Pancreas[MDC crossing]: “Diseases and Disorders of the Hepatobiliary System and Pancreas — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 2,481 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

• Annular, pancreas (congenital)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes

• Q45 — Other congenital malformations of digestive system[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• Q45.0 — Agenesis, aplasia and hypoplasia of pancreas[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• Q45.2 — Congenital pancreatic cyst[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• Q45.3 — Other congenital malformations of pancreas and pancreatic duct[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• Q45.8 — Other specified congenital malformations of digestive system[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• Q45.9 — Congenital malformation of digestive system, unspecified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

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

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

Nearest Codes in This Family

Official ICD-10-CM classifications closest to Q45.1 in its code family, with their registry titles.

• Q45 — Other congenital malformations of digestive system
• Q45.0 — Agenesis, aplasia and hypoplasia of pancreas
• Q45.2 — Congenital pancreatic cyst
• Q45.3 — Other congenital malformations of pancreas and pancreatic duct
• Q45.8 — Other specified congenital malformations of digestive system
• Q45.9 — Congenital malformation of digestive system, unspecified

View all codes in the Q45 family