ICD-10-CM · Spine

M00.28

Pyogenic arthritis of the vertebrae caused by streptococcal species other than Streptococcus pneumoniae or Group A streptococcus — classified under the infectious arthropathies block of the musculoskeletal chapter.

Verified May 8, 2026 · 5 sources ↓

Status: Billable
Chapter: 13
Related CPT: 8
Region: Spine

Drawn from CDCICD10DataAAPCCMS

Documentation tips

What should appear in the chart to support M00.28.

Source · Editorial brief grounded in 5 cited references ↓

Specify the streptococcal species or group in the medical record (e.g., Group B Strep, viridans streptococcus) so the correct B95.x organism code can be appended.
Document the vertebral level(s) involved — cervical, thoracic, lumbar — even though M00.28 does not further subdivide by spinal region; this supports clinical necessity for imaging and surgical procedures.
Record culture and sensitivity results from blood, joint aspirate, or biopsy to confirm streptococcal etiology and justify the infectious arthropathy code over noninfectious spinal diagnoses.
Distinguish between septic arthritis of the vertebral joint, vertebral osteomyelitis, and discitis in the provider's note — these map to different ICD-10-CM categories and are not interchangeable.
Note any prior antibiotic therapy or immunocompromised status; these affect clinical reasoning documentation and may support additional comorbidity codes.

Related CPT procedures

Procedure codes commonly billed with M00.28. Linking the right diagnosis to the right procedure is what establishes medical necessity.

Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis

22010 $950.92

Open incision and drainage of a deep subfascial abscess located along the posterior cervical, thoracic, or cervicothoracic spine

22015 $921.86

Open incision and drainage of a deep subfascial abscess along the posterior lumbar, sacral, or lumbosacral spine.

22840 $668.35

Posterior non-segmental instrumentation placed during spinal surgery, using rods, hooks, or wires that span multiple vertebral levels without anchoring at each intervening segment.

63030 $898.15

Single-interspace lumbar laminotomy with nerve root decompression, including partial facetectomy, foraminotomy, and/or herniated disc excision performed via open surgical technique.

72148 $191.72

Non-contrast MRI of the lumbar spine used to evaluate disc pathology, spinal stenosis, nerve root compression, and other structural abnormalities without administration of contrast material.

72020 $23.71

Single-view radiologic examination of the spine at a specified level.

87070 View procedure details

87081 View procedure details

Common coding pitfalls

The recurring mistakes coders make with M00.28 and adjacent codes.

Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓

Omitting the B95.x causative organism code — ICD-10-CM instructs 'use additional code to identify bacterial agent'; claims submitted without it are incomplete.
Using M00.28 for a prosthetic spinal implant infection — the M00 Type 2 Excludes note redirects those cases to T84.5- with an organism code.
Confusing septic arthritis of the vertebrae (M00.28) with vertebral osteomyelitis (M46.2x-) or infective discitis (M46.3x-/M46.4x-) — the provider's documentation must clearly identify the joint as the primary infected structure.
Selecting M00.28 when the organism is Streptococcus pneumoniae — that maps to M00.1x (pneumococcal arthritis), not M00.2x.
Applying a 7th-character extension — M00.28 is an M-code and does not take 7th-character encounter extensions (A/D/S); adding one creates an invalid code.

Clinical context

Source · Editorial summary grounded in 5 cited references ↓

M00.28 applies when a patient has confirmed or presumptively diagnosed streptococcal septic arthritis of one or more vertebral joints, and the causative organism is a streptococcal species not captured by other M00.2 subcategories (e.g., Group B, Group C, Group G, or viridans streptococci). The '8' digit designates the vertebral site within the M00.2 parent category. This is a rare but serious presentation — vertebral septic arthritis typically involves the intervertebral disc space and adjacent end plates, and clinical documentation should distinguish it from vertebral osteomyelitis (M46.2x-) or discitis (M46.3x-/M46.4x-), which are separate entities requiring different codes.

Because this is an infectious arthropathy, ICD-10-CM instructs coders to use an additional code to identify the causative organism (B95-B96 series). For streptococcal species, select from B95.0–B95.5 based on the specific group or species identified on culture. If blood or joint fluid culture specifies Group B strep, use B95.1; unspecified streptococcus defaults to B95.5. Failing to append the organism code leaves the claim incomplete and may trigger a medical necessity query.

The M00 category carries a Type 2 Excludes note for infection and inflammatory reaction due to an internal joint prosthesis (T84.5-). If the patient has a spinal implant and develops streptococcal infection at that site, code from T84.5- instead and add the organism code. Do not use M00.28 for prosthesis-related spinal infections.

Sibling codes

Other billable codes under M00.2 (laterality / anatomic variants).

M00.29

Other streptococcal polyarthritis

M00.20

Other streptococcal arthritis, unspecified joint

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 5 cited references ↓

01Do I always need to add a second code when billing M00.28?

Yes. ICD-10-CM requires an additional code from B95.0–B95.5 to identify the specific streptococcal organism. Submitting M00.28 alone is technically incomplete per the Tabular List instruction.

02Which B95 code pairs with M00.28 when the species is unspecified streptococcus?

Use B95.5 (Unspecified streptococcus as the cause of diseases classified elsewhere) when the culture confirms streptococcus but does not specify the group or species.

03Can I use M00.28 for streptococcal pneumoniae arthritis of the spine?

No. Streptococcus pneumoniae arthritis maps to M00.1x (pneumococcal arthritis). M00.28 is reserved for other streptococcal species — Groups B, C, G, viridans, etc.

04What is the difference between M00.28 and M46.28 for vertebral infection?

M00.28 codes infectious arthritis of the vertebral joint itself. M46.28 codes osteomyelitis of the vertebrae. The provider's documentation must identify whether the infection is primarily in the joint, the bone, or the disc — they are not interchangeable.

05Should I use M00.28 if the patient has a spinal fusion cage or implant and develops streptococcal infection?

No. The M00 category excludes infection related to internal joint prosthesis. Code instead from T84.5- (Infection and inflammatory reaction due to internal joint prosthesis) with the appropriate B95.x organism code.

06Does M00.28 require a 7th character for encounter type?

No. M-codes in Chapter 13 do not use 7th-character extensions. Those are reserved for injury codes (S-codes) where A = initial, D = subsequent, S = sequela. Adding a 7th character to M00.28 creates an invalid code.

07What imaging supports M00.28 at audit?

MRI of the spine is the gold standard for demonstrating vertebral joint involvement in septic arthritis. Document MRI findings such as joint effusion, end-plate changes, or periarticular signal abnormality alongside culture results confirming streptococcal etiology.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira AI Scribe

Mira's AI scribe captures the treating provider's documentation of vertebral joint infection including the suspected or confirmed streptococcal species, spinal levels involved, culture/sensitivity results, and any notation of prosthetic hardware at the site. This prevents rejection from a missing B95.x organism code, guards against miscoding to vertebral osteomyelitis or discitis, and ensures the record distinguishes native joint infection from implant-related infection before code assignment.

See how Mira captures M00.28 documentation