MS-DRGs in MS-DRGs not assigned to an MDC
Weights in this category range from 1.1040 (DRG 989) to 4.7440 (DRG 981); the change column compares FY2027 with FY2026.
| DRG | Title | Type | Weight | GMLOS | Change |
|---|---|---|---|---|---|
| 981 | Extensive O.R. Procedures Unrelated to Principal Diagnosis with MCC | Surgical | 4.7440 | 8.4 | +1.1% |
| 982 | Extensive O.R. Procedures Unrelated to Principal Diagnosis with CC | Surgical | 2.4250 | 3.9 | -1.3% |
| 983 | Extensive O.R. Procedures Unrelated to Principal Diagnosis without CC/MCC | Surgical | 1.6140 | 1.9 | -5.8% |
| 987 | Non-Extensive O.R. Procedures Unrelated to Principal Diagnosis with MCC | Surgical | 3.3520 | 7.7 | -2.2% |
| 988 | Non-Extensive O.R. Procedures Unrelated to Principal Diagnosis with CC | Surgical | 1.6470 | 4.0 | +0.2% |
| 989 | Non-Extensive O.R. Procedures Unrelated to Principal Diagnosis without CC/MCC | Surgical | 1.1040 | 2.1 | -7.9% |
| 998 | Principal Diagnosis Invalid As Discharge Diagnosis | ** | n/a | n/a | new |
| 999 | Ungroupable | ** | n/a | n/a | new |
How to read this table
The relative weight is the payment multiplier CMS applies to a hospital's wage-adjusted standardized amount; a weight of 2.0 pays roughly twice an average inpatient case before outliers and add-ons. Geometric mean length of stay is the figure used in post-acute transfer calculations, so stays shorter than it in a transfer DRG are paid per diem. The change column compares the FY2027 final weight with FY2026; moves larger than two percent usually come from code reassignments in the final rule's Table 6 series or from updated cost data, and are worth re-checking in contract models and budgets before October 1. Surgical DRGs require a qualifying operating-room procedure; medical DRGs are reached when no such procedure is coded.
Frequently asked questions
How many MS-DRGs are in MS-DRGs not assigned to an MDC?
8 MS-DRGs are assigned to MS-DRGs not assigned to an MDC (MS-DRGs not assigned to an MDC) in the FY2027 v44 grouper: 6 surgical and 0 medical.
Which MS-DRGs not assigned to an MDC DRG has the highest weight?
DRG 981, Extensive O.R. Procedures Unrelated to Principal Diagnosis with MCC, carries the highest FY2027 relative weight in this category at 4.7440; the lowest is DRG 989 at 1.1040.
How is a stay assigned to this MDC?
Pre-MDC and unassigned groups are selected before the principal-diagnosis MDC logic, typically on the basis of a transplant, ECMO, tracheostomy or ungroupable record.
Sources
Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-01. Verify against the primary file before billing or contracting decisions.
- IPPS FY2027 Final Rule Table 5 (CMS-1849-F)Version v44 FY2027 · effective 2026-10-01 · file CMS-1849-F Table 5.txtSHA-256 01003dd571c1e2f5…
- IPPS FY2026 Final Rule Table 5 (CMS-1833-F)Version v43 FY2026 · effective 2025-10-01 · file CMS-1833-F Table 5.txtSHA-256 bf8c390d14b3cd3e…
Disclaimer
Operational reference compiled from CMS publications. Relative weights are national factors; actual payment depends on hospital-specific rates and adjustments. Not legal, clinical or billing advice.