309 MS-DRG: CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITH CC
MS-DRG 309 groups Medicare inpatient hospital stays for: CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITH CC. This is a medical MS-DRG. It falls under MDC 05 (Diseases and Disorders of the Circulatory System).
Payment & Classification Data
Official CMS values from the FY2027 IPPS Final Rule Table 5.
| Major Diagnostic Category | MDC 05 — Diseases and Disorders of the Circulatory System |
| DRG Type | Medical |
| Severity Level | CC |
| Relative Weight | 0.7316 |
| Relative Weight (10% Cap Applied) | 0.7316 |
| Geometric Mean Length of Stay | 2.2 days |
| Arithmetic Mean Length of Stay | 2.7 days |
| Post-Acute Transfer DRG | No |
| Special Pay Transfer DRG | No |
Defining Codes (FY2027)
61 diagnosis codes can drive assignment here: I44.0, I44.1, I44.2, I44.30, I44.39, I44.4, I44.5, I44.60, I44.69, I44.7, I45.0, I45.10 and 49 more.
From the CMS MS-DRG Definitions Manual (Appendices B and E). Assignment also depends on severity, discharge status and the rest of the claim.
Contextual Map
Every relationship of 309 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.
Major Diagnostic Category
- MDC 05 — Diseases and Disorders of the Circulatory System[MDC]— CMS MS-DRG Definitions Manual · FY2027
Defining diagnoses (61)
- I44.0 — Atrioventricular block, first degree[Grouper diagnosis]— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
- I44.1 — Atrioventricular block, second degree[Grouper diagnosis]— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
- I44.2 — Atrioventricular block, complete[Grouper diagnosis]— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
- I44.30 — Unspecified atrioventricular block[Grouper diagnosis]— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
- I44.39 — Other atrioventricular block[Grouper diagnosis]— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
- I44.4 — Left anterior fascicular block[Grouper diagnosis]— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
- I44.5 — Left posterior fascicular block[Grouper diagnosis]— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
- I44.60 — Unspecified fascicular block[Grouper diagnosis]— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
- and 53 more
DRG family
- DRG 308 — CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITH MCC[DRG family]: “CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITH MCC — same CMS DRG family (308-310), split by severity.”— CMS MS-DRG Definitions Manual (DRG family 308-310) · FY2027
- DRG 310 — CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITHOUT CC/MCC[DRG family]: “CARDIAC ARRHYTHMIA AND CONDUCTION DISORDERS WITHOUT CC/MCC — same CMS DRG family (308-310), split by severity.”— CMS MS-DRG Definitions Manual (DRG family 308-310) · FY2027
Read from: CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v44. All data sources · How to read the labels · How MedCoder verifies its implementation
Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 20, 2026 · All releases and sources