551 — Medical Back Problems with MCC

MS-DRG 551, Medical Back Problems with MCC, is a medical DRG in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue) under MS-DRG version 44.0, which applies to inpatient discharges from October 1, 2026 through September 30, 2027.

Its FY2027 relative weight is 1.6358, so Medicare's base payment for this DRG is about 1.64 times the average inpatient case, before hospital-specific adjustments. The geometric mean length of stay is 4.4 days and the arithmetic mean is 5.7 days.

It belongs to a 2-level severity family: DRG 551 (with MCC, weight 1.6358) and DRG 552 (without MCC, weight 0.9584). The highest-severity level carries 1.7 times the weight of the lowest, which is why documenting CC and MCC conditions matters.

It is subject to Medicare's post-acute care transfer policy, so payment can be reduced when a patient with a shorter-than-average stay is discharged to a skilled nursing facility, home health or another post-acute setting.

1,170 ICD-10-CM diagnosis codes are part of this DRG's grouping logic; they are listed below.