M25.552: Pain in left hip

M25.552 carries no CMS-HCC v28 mapping.

No code in subcategory M25.55 maps to a v28 category. The three v28 categories in this clinical area are HCC 92 for bone, joint, muscle and severe soft tissue infections and necrosis, HCC 93 for rheumatoid arthritis and other specified inflammatory rheumatic disorders, and HCC 94 for systemic lupus erythematosus and other specified systemic connective tissue disorders. A joint pain symptom sits outside all three.

Naming the side changes nothing in the risk score. Moving from M25.559 to M25.552 is a compliance and medical necessity gain rather than a risk adjustment gain.

Naming the cause does not reliably change it either, which sets the hip apart from sites where the differential carries risk weight. Hip osteoarthritis at M16.12 carries no v28 HCC. Trochanteric bursitis at M70.62 carries none. A non-traumatic hip labral lesion at M24.152 carries none.

Idiopathic aseptic necrosis of the left femur at M87.052 is the exception inside this differential. It maps to HCC 92 in v28, where it mapped to HCC 39 in v24. HCC 92 covers bone, joint, muscle and severe soft tissue infections and necrosis. The infective and necrotic causes of hip pain are where the v28 weight sits in this clinical area.

CMS calculates 100 percent of CY2026 risk scores using the 2024 CMS-HCC model, completing the three year phase in, per the CY2026 Medicare Advantage and Part D Rate Announcement.

MS-DRG 555: signs and symptoms of musculoskeletal system and connective tissue with MCC.

MS-DRG 556: signs and symptoms of musculoskeletal system and connective tissue without MCC.

An inpatient admission with M25.552 as the principal diagnosis groups to MS-DRG 555 or 556 in MDC 08 under the FY2027 MS-DRG v44 grouper. Both sit in the medical partition.

The pair splits on MCC alone. There is no CC tier between 555 and 556. Severity weight on such an admission comes from comorbidities documented elsewhere in the record rather than from the hip pain code.

A symptom code in the principal position is what produces this pair. Where the admission works the hip pain up to a cause, that cause becomes the principal diagnosis and the admission leaves 555 and 556.

The differential moves the case to a different pair. Hip osteoarthritis groups to MS-DRG 553 or 554, bone diseases and arthropathies with or without MCC. Trochanteric bursitis groups to MS-DRG 557 or 558, tendonitis, myositis and bursitis with or without MCC. A hip sprain at the initial encounter groups to MS-DRG 537 or 538, sprains, strains, and dislocations of hip, pelvis and thigh with CC/MCC or without CC/MCC. The sprain pair splits on CC as well as MCC. The symptom pair at 555 and 556 does not.

M25.552 is a billable code and is valid on a claim when the record supports no more specific code.

The FY2027 ICD-10-CM Official Guidelines, section I.B.18, state that sign, symptom and unspecified codes have acceptable, even necessary, uses. Where a definitive diagnosis has not been established by the end of the encounter, reporting the sign or symptom code is appropriate.

Section I.B.13 sets a tighter rule for the side than section I.B.18 sets for the diagnosis. It states that codes for the unspecified side should rarely be used. It permits them only where the record cannot establish the affected side and clarification cannot be obtained. It permits the side to be taken from the documentation of clinicians other than the patient's provider. Conflicting documentation calls for a provider query.

Section I.C.13.a states that most chapter 13 codes have site and laterality designations. The site represents the bone, joint or muscle involved.

M25.552 records the side. What it gives up is the diagnosis. Hip pain is a presenting sign with a large coded differential. Every entry in that differential carries its own code and its own coverage terms.

Osteoarthritis is one entry in it. Category M16 is the first place to look when a hip pain code is being reviewed. Once the provider documents osteoarthritis of the left hip, M16.12 replaces M25.552.

Section I.B.4 of the Official Guidelines states that codes describing symptoms and signs are acceptable for reporting when a related definitive diagnosis has not been established by the provider. Section I.B.5 adds that signs and symptoms associated routinely with a disease process should not be assigned as additional codes.

M25.559 is the larger loss. It gives up the side on a joint the examining provider has already identified. The unspecified side code therefore records a gap in the note rather than a gap in clinical knowledge. One word recovers it.

Bilateral involvement is a third loss. Subcategory M25.55 carries no bilateral code. Both hips take M25.551 and M25.552 together, never M25.559.

Groin is a fourth. A note that says only left groin pain reads to the Alphabetic Index as abdominal pain and lands on R10.32, several chapters away from the hip.

M25.552 carries no severity designation. It appears in neither Appendix G, the CC list, nor Appendix H, the MCC list, of the ICD-10 MS-DRG Definitions Manual Version 44.0. A case reaches the higher tier of its DRG pair on a designation carried by another diagnosis.