Orthopedic billing can become complicated quickly. A single patient encounter may involve an office visit, diagnostic imaging, an injection, fracture management, surgery, implants, modifiers, and postoperative care. Each service must be supported by the right documentation, CPT code, ICD-10-CM diagnosis, modifier, payer policy, and medical necessity.
This Orthopedic Billing & CPT Codes Cheat Sheet 2026 gives orthopedic surgeons, physicians, coders, billers, and practice managers a practical reference for frequently used orthopedic CPT codes, modifiers, global surgery rules, NCCI edits, documentation requirements, prior authorization, and common billing errors.
The 2026 CPT code set became effective on January 1, 2026. The AMA reports 418 total changes across CPT, including 288 new codes, 84 deletions, and 46 revisions. Not every change affects orthopedics, but orthopedic practices still need to update coding references, payer edits, billing software, and clinical documentation templates.
Coding note: This cheat sheet is an educational reference, not a replacement for the current AMA CPT codebook, CMS guidance, NCCI edits, Medicare Administrative Contractor policies, or individual payer requirements.
Why is Orthopedic Coding so Complex?
Orthopedics covers bones, joints, muscles, ligaments, tendons, nerves, fractures, spinal conditions, sports injuries, joint replacements, arthroscopy, injections, rehabilitation-related services, and other musculoskeletal conditions.
That creates several coding challenges.
A procedure can change based on the anatomical site, surgical approach, fracture type, laterality, implant used, number of structures treated, whether imaging guidance was used, and whether another service was performed during the same encounter.
Orthopedic claims are also affected by:
- CPT and HCPCS coding rules
- ICD-10-CM diagnosis specificity
- NCCI procedure-to-procedure edits
- Global surgical periods
- Medical necessity
- Prior authorization
- Modifier requirements
- Laterality
- Bundling rules
- Payer-specific coverage policies
- Place of service
- Implant documentation
- Operative-note documentation
CMS continues to maintain annual NCCI coding policies, with its 2026 Medicare NCCI Policy Manual effective January 1, 2026.
How to Use this Guide
Use this orthopedic CPT cheat sheet as a quick reference when reviewing common services, but code from the complete medical record.
Before submitting an orthopedic claim, confirm:
- What service was actually performed?
- Which anatomical structure was treated?
- Was the procedure unilateral or bilateral?
- Was it open, percutaneous, arthroscopic, or another approach?
- Does the operative report support the selected CPT code?
- Does the ICD-10-CM diagnosis establish medical necessity?
- Are multiple procedures subject to an NCCI edit?
- Is a modifier required?
- Is the patient within a global surgical period?
- Did the payer require prior authorization?
The final code selection should always follow the current code set and the payer’s rules.
Orthopedic Medical Billing
Orthopedic medical billing begins before the patient receives treatment.
Insurance eligibility, benefits, referral requirements, authorization, patient demographics, medical necessity, coding, claim submission, payment posting, denial management, and accounts receivable follow-up all affect whether the practice gets paid correctly.
A clean orthopedic revenue cycle typically follows this workflow:
Patient registration → Eligibility verification → Prior authorization → Documentation → CPT/ICD-10 coding → Charge entry → Claim scrubbing → Submission → Payment posting → Denial follow-up → AR management
Because orthopedic procedures often have higher reimbursement values and complex surgical coding rules, errors early in the process can create expensive denials later.
Why Do Orthopedic CPT Codes Matter?
CPT codes communicate the procedures and professional services performed by the orthopedic provider.
Orthopedic coding can involve several sections of CPT rather than one isolated code range. Depending on the encounter, a claim may include E/M, musculoskeletal surgery, injections, diagnostic imaging, nerve blocks, casting, or other related services.
Correct CPT coding helps support:
- Accurate claim submission
- Appropriate reimbursement
- Medical necessity reviews
- Prior authorization matching
- NCCI compliance
- Global surgery processing
- Cleaner claims
- Reduced coding-related denials
- More reliable revenue cycle reporting
The AMA identifies CPT as the standard code set used to report medical procedures and services, with the 2026 code set containing more than 11,520 codes.
What Changed in Orthopedic CPT Coding for 2026?
A major gap in many orthopedic CPT cheat sheets is that they carry a 2026 title without explaining what actually changed in 2026.
Two notable new musculoskeletal CPT codes for 2026 are:
| CPT Code | 2026 Orthopedic Coding Area |
| 27458 | Femoral osteotomy involving an externally controlled intramedullary lengthening device |
| 27713 | Tibial osteotomy, including the fibula when performed, involving an externally controlled intramedullary lengthening device |
Both became effective January 1, 2026.
2026 Sacroiliac Joint Coding Changes
CPT 27278 and 27279 also received updated language for SI joint arthrodesis.
In practical terms, the current coding distinction focuses on how the device is positioned and whether cortical bone is pierced. Practices performing SI joint procedures should review the complete 2026 descriptors and documentation requirements instead of relying on older terminology.
These changes show why an orthopedic practice should not simply reuse its 2025 charge sheet in 2026.
Types of Orthopedic CPT Codes
The most frequently encountered orthopedic coding categories include:
Evaluation and Management Codes
Common office E/M ranges include:
- 99202–99205 — New patient office/outpatient visits
- 99211–99215 — Established patient office/outpatient visits
The correct level depends on applicable E/M rules, including medical decision-making or time when permitted.
Joint Aspiration and Injection Codes
Common examples include:
- 20610 — Major joint or bursa aspiration/injection without ultrasound guidance
- 20611 — Major joint or bursa aspiration/injection with ultrasound guidance when all code requirements are satisfied
Do not automatically add a separate ultrasound guidance code when the primary procedure code already incorporates the guidance service.
Arthroscopy Codes
Orthopedic arthroscopy commonly involves CPT codes in the 298xx range, including knee and shoulder procedures.
Fracture Care Codes
Fracture coding depends on the bone, location, displacement, treatment method, manipulation, fixation technique, and whether the procedure is open or closed.
Joint Replacement Codes
Hip and knee arthroplasty are among the most important high-value orthopedic procedures.
Spine Surgery Codes
Spinal decompression, fusion, instrumentation, discectomy, SI joint procedures, and related services require detailed operative documentation and careful bundling review.
Most Commonly Used Orthopedic CPT Codes
The following table provides a practical quick reference. It intentionally uses simplified service descriptions; coders should verify the full 2026 CPT descriptor before billing.
| CPT Code | Common Orthopedic Service |
| 99202–99205 | New patient office/outpatient E/M |
| 99211–99215 | Established patient office/outpatient E/M |
| 20610 | Major joint/bursa aspiration or injection without ultrasound guidance |
| 20611 | Major joint/bursa aspiration or injection with ultrasound guidance |
| 29881 | Knee arthroscopy with meniscectomy |
| 29882 | Knee arthroscopy with meniscus repair |
| 29888 | Arthroscopic ACL reconstruction |
| 29827 | Arthroscopic rotator cuff repair |
| 29826 | Arthroscopic shoulder decompression/acromioplasty add-on service |
| 27130 | Total hip arthroplasty |
| 27447 | Total knee arthroplasty |
| 27486 | Revision total knee arthroplasty involving one component |
| 27245 | Treatment of certain proximal femoral fractures using an intramedullary implant |
| 27506 | Open treatment of femoral shaft fracture with intramedullary fixation |
| 27758 | Open treatment of tibial shaft fracture with plate/screw fixation |
| 64721 | Open carpal tunnel release |
| 29848 | Endoscopic carpal tunnel release |
| 63030 | Lumbar laminotomy/discectomy |
| 63047 | Lumbar decompressive laminectomy, applicable segment |
| 73562 | Knee radiograph, three views |
| 72100 | Lumbar spine radiograph, two or three views |
One important coding detail is CPT 29826: it is an add-on code, not a stand-alone primary procedure. It should be reported only when its requirements and an appropriate primary shoulder arthroscopy service are documented.
Similarly, CPT 27506 relates to the femoral shaft, while CPT 27758 addresses open treatment of a tibial shaft fracture with plate/screw fixation.
CPT Codes for Orthopedic Surgery
Knee Surgery CPT Codes
Frequently encountered knee procedure codes include:
- 27447 — Total knee arthroplasty
- 27486 — Revision knee arthroplasty involving one component
- 29881 — Arthroscopic meniscectomy
- 29882 — Arthroscopic meniscal repair
- 29888 — Arthroscopic ACL reconstruction
The operative report should clearly identify the compartment, tissue treated, surgical technique, laterality, implants, and any separately performed procedures.
Hip Surgery CPT Codes
Common codes include:
- 27130 — Total hip arthroplasty
- 27245 — Certain proximal femoral fracture treatments involving intramedullary fixation
Documentation should support the diagnosis, side, surgical approach, implants, and exact fracture or joint pathology treated.
Shoulder Surgery CPT Codes
Frequently reported codes include:
- 29827 — Arthroscopic rotator cuff repair
- 29826 — Arthroscopic decompression/acromioplasty add-on service when appropriately performed
- Other shoulder arthroscopy codes depending on the specific repair or procedure
Do not assume every service documented during an arthroscopy is separately payable. NCCI and CPT bundling rules must be reviewed.
Hand and Wrist CPT Codes
Common examples include:
- 64721 — Open carpal tunnel release
- 29848 — Endoscopic carpal tunnel release
Laterality and operative technique should be clearly documented.
Spine Surgery CPT Codes
Common orthopedic and spine coding areas include:
- Lumbar decompression
- Laminotomy/discectomy
- Fusion
- Instrumentation
- Bone grafting
- SI joint arthrodesis
- Vertebral procedures
Spine coding is particularly sensitive to spinal level, surgical approach, number of segments, instrumentation, grafting, and add-on-code rules.
Orthopedic Billing Codes
CPT alone does not make an orthopedic claim complete.
The CPT procedure must generally be supported by an appropriate ICD-10-CM diagnosis demonstrating why the service was medically necessary.
Orthopedic ICD-10 coding commonly requires additional specificity for:
- Right versus left side
- Specific joint or bone
- Type of injury
- Displaced versus nondisplaced fracture
- Open versus closed fracture where applicable
- Encounter status
- Healing status
- Traumatic versus pathological fracture
- Osteoarthritis location
- Postoperative complications
For many fractures, the seventh character communicates the phase of treatment. Under FY 2026 ICD-10-CM guidance, an A seventh character is generally associated with active treatment, while D is generally used for routine care during the healing or recovery phase after active treatment is completed.
Important September/October 2026 ICD-10 Update
For dates of service through September 30, 2026, practices should use the applicable FY 2026 ICD-10-CM files.
Beginning October 1, 2026, FY 2027 ICD-10-CM codes become effective for patient encounters. This is especially important for practices reading a “2026” cheat sheet late in the year.
Common Modifiers
Modifiers are a major source of orthopedic denials.
Common modifiers include:
| Modifier | General Orthopedic Use |
| RT | Right side |
| LT | Left side |
| 50 | Bilateral procedure when appropriate |
| 25 | Significant, separately identifiable E/M service on the same day as another procedure |
| 57 | Decision for major surgery when requirements are met |
| 59 | Distinct procedural service when justified |
| XE | Separate encounter |
| XP | Separate practitioner |
| XS | Separate structure |
| XU | Unusual non-overlapping service |
| 24 | Unrelated E/M service during postoperative period |
| 58 | Staged or related procedure/service during postoperative period when criteria are met |
| 78 | Unplanned return to an operating/procedure room for a related service during postoperative period |
| 79 | Unrelated procedure during postoperative period |
CMS specifically recognizes modifiers including 24, 25, 57, 58, 78, 79, 59, XE, XP, XS, XU, RT, LT and other anatomical modifiers in appropriate NCCI circumstances. A modifier should never be added simply to force an edited code pair through the payer’s system.
All About Modifier 25
Modifier 25 is one of the most important modifiers for orthopedic offices because injections and minor procedures are frequently performed during office visits.
It is appended to the E/M service, not the procedure, when the patient’s condition requires a significant and separately identifiable E/M service beyond the normal work associated with the procedure.
For example, a patient may present for evaluation of new knee pain. The orthopedic physician completes a medically necessary evaluation and subsequently determines that an injection should be performed.
A separately billable E/M service may be possible when documentation supports the distinct evaluation.
However, simply discussing or performing the normal pre-procedure assessment does not automatically justify modifier 25.
Difference Between Modifier 25 and Modifier 57
Although both modifiers relate to E/M services associated with procedures, they serve different purposes.
Modifier 25 is generally associated with a significant, separately identifiable E/M service on the same day as a minor procedure or another qualifying service.
Modifier 57 is associated with the E/M service that results in the decision to perform a major surgery, subject to applicable global surgery and payer rules.
CMS guidance notes that modifier 57 is associated with major procedures carrying a 90-day global period rather than minor-procedure decisions.
Bundling and Unbundling
Orthopedic practices frequently report multiple procedures during one operative session, making bundling rules critical.
CMS National Correct Coding Initiative Procedure-to-Procedure edits identify code combinations that generally should not be reported together unless appropriate circumstances support separate reporting.
A modifier such as 59, XS, XE, XP, or XU should only be used when the clinical situation and documentation genuinely support a distinct service.
CMS specifically warns that a modifier should not be appended solely to bypass an NCCI edit.
Before submitting multiple orthopedic procedure codes:
- Check current NCCI edits.
- Review the operative report.
- Confirm whether services occurred at separate anatomical sites.
- Determine whether one procedure is inherent to another.
- Confirm whether an add-on code is being used correctly.
- Verify payer-specific bundling policies.
- Add a modifier only when documentation supports it.
Global Period
Global surgery rules affect many orthopedic procedures.
CMS uses several indicators, including:
- 000 — Day-of-procedure global concept
- 010 — 10-day postoperative period
- 090 — Major surgery with a 90-day postoperative period
- XXX — Global surgery concept does not apply
For a 90-day global surgery, Medicare generally includes one day of preoperative care plus the 90-day postoperative period in the global payment.
Routine postoperative visits related to the surgery generally should not be billed separately.
However, separate reporting may sometimes be appropriate when the requirements for modifiers such as 24, 58, 78, or 79 are satisfied and documented.
Benefit and Coverage Verification
Eligibility verification should happen before treatment whenever possible.
Orthopedic staff should confirm:
- Active insurance coverage
- Deductible
- Copayment
- Coinsurance
- Referral requirements
- Network status
- Procedure coverage
- Imaging benefits
- Therapy benefits
- DME benefits
- Authorization requirements
- Surgery benefits
High-cost orthopedic services such as joint replacement, spinal procedures, advanced imaging, implants, and certain injections may be subject to prior authorization.
Eligibility verification does not automatically mean a service is covered, so payer-specific benefits and authorization requirements still need to be checked.
Patient Information Confirmation
Small demographic errors can delay otherwise correct orthopedic claims.
Verify:
- Patient’s legal name
- Date of birth
- Address
- Insurance member ID
- Group number
- Payer information
- Referring provider information when required
- Coordination of benefits
- Accident or workers’ compensation information when applicable
Correct registration data creates the foundation for a cleaner claim.
Timely and Specific Coding
Orthopedic coding should be completed from the provider’s actual documentation rather than from an appointment description or procedure schedule.
The coder should understand:
- Anatomy
- Laterality
- Surgical approach
- Procedures performed
- Fracture location
- Number of levels or segments
- Implants
- Grafts
- Imaging guidance
- Postoperative status
- Medical necessity
Coding from incomplete documentation increases both undercoding and overcoding risks.
Common Mistakes in Orthopedic Medical Billing
Bundling Errors
Separately billing components already included in a comprehensive procedure can create denials, overpayments, and compliance concerns.
Run appropriate claims through current NCCI edits before submission.
Not Verifying Medical Insurance
Expired coverage, incorrect payer information, or missing benefits verification can cause denials before coding accuracy even becomes relevant.
Payer Guidelines
Medicare, Medicaid, Medicare Advantage plans, workers’ compensation programs, and commercial insurers can have different authorization, coverage, modifier, documentation, and billing requirements.
Do not assume that a coding rule accepted by one payer will automatically be accepted by another.
Inappropriate Documentation
Vague operative notes create coding problems.
For example, an orthopedic surgery note should identify enough clinical detail to support the exact service billed rather than simply saying that a “repair” or “decompression” was performed.
Not Coding to the Highest Degree of Specificity
Orthopedic ICD-10-CM coding frequently depends on precise anatomy and laterality.
Unspecified diagnosis codes should not be selected merely because they are faster when the medical record supports greater specificity.
Failure to Submit Updated and New Codes
Using deleted or outdated CPT and ICD-10-CM codes can result in immediate rejections.
2026 practices should ensure their EHR, practice management system, claim scrubber, charge sheets, coding software, and internal reference materials are current.
Incorrect Modifiers
Common errors include:
- Applying modifier 59 automatically
- Missing RT/LT
- Using modifier 25 without a separately identifiable E/M service
- Using modifier 57 for a minor procedure
- Applying modifier 50 where payer methodology requires a different reporting method
- Ignoring global surgery modifiers
Upcoding/Downcoding E&M Services
E/M levels should be determined by the applicable coding guidelines and provider documentation.
Selecting a higher level without support creates compliance risk. Selecting a lower level despite documentation supporting a higher level can create revenue leakage.
Essential Documentation and Coding Rules Every Orthopedic Provider Should Know
Strong documentation should clearly communicate:
Anatomical location: Identify the exact bone, joint, tendon, ligament, nerve, or spinal level.
Laterality: Document right, left, or bilateral treatment.
Diagnosis: Explain the condition or injury requiring treatment.
Procedure performed: Describe what was actually done rather than relying only on the procedure title.
Surgical approach: Document whether the procedure was open, arthroscopic, percutaneous, or another applicable approach.
Implants and devices: Identify clinically relevant implant information when required.
Fracture details: Document the site, characteristics, treatment type, and stage of care.
Medical necessity: Explain why the procedure was reasonable and necessary.
Separate procedures: If services are reported separately, the note should demonstrate why they were distinct.
E/M services: Documentation should support the level and any modifier appended.
The claim should tell the same clinical story as the patient’s chart.
Orthopedic Claim Denials: What Billing Teams Should Watch
A strong orthopedic billing workflow should track denial patterns instead of treating every denial as an isolated event.
Common categories include:
- Authorization denials
- Medical necessity denials
- Incorrect modifiers
- Bundled procedures
- Diagnosis/procedure mismatch
- Eligibility issues
- Duplicate claims
- Global-period denials
- Missing documentation
- Untimely filing
- Incorrect laterality
- Non-covered services
Denial management should include root-cause analysis.
If the same CPT/modifier combination is repeatedly denied, the practice should review its coding policy, documentation, payer contract, claim scrubber, and staff workflow before simply resubmitting the same claim.
Where Can I Get a List of CPT Codes?
The American Medical Association maintains the CPT code set and publishes the current CPT resources. The CPT 2026 code set took effect January 1, 2026.
CMS also publishes essential resources used alongside CPT coding, including:
- Medicare Physician Fee Schedule files
- NCCI Policy Manual
- NCCI procedure edits
- HCPCS information
- ICD-10 files
- Medicare coverage policies
CMS has already published 2026 Physician Fee Schedule payment files and 2026 NCCI guidance.
Orthopedic coders should also review payer portals and relevant specialty guidance rather than relying on an online cheat sheet alone.
Complexities in Orthopedic Medical Billing
Orthopedic practices often combine high procedure volume with high claim value.
Revenue cycle problems can develop when clinical, coding, and billing teams operate separately.
For example:
A surgeon may document a procedure correctly, but the billing team may miss authorization.
The authorization may be correct, but the CPT code submitted may not match the authorized service.
The CPT code may be correct, but the diagnosis may lack laterality or specificity.
The codes may be correct, but an NCCI edit may bundle two services.
The claim may pass coding edits but still be denied because the patient is inside a global period.
Effective orthopedic revenue cycle management therefore requires coordination across front-desk operations, coding, claims, payment posting, denial management, AR follow-up, and provider documentation.
Outsourcing Orthopedic Billing and Coding
Orthopedic practices experiencing recurring denials, aging AR, delayed coding, staffing shortages, or inconsistent collections may consider specialized orthopedic medical billing services.
The objective should not simply be to submit more claims. A strong orthopedic billing partner should help connect:
- Eligibility verification
- Prior authorization
- Medical coding
- CPT and ICD-10 validation
- Modifier review
- Claim submission
- Payment posting
- Denial management
- AR follow-up
- Billing audits
- Revenue cycle reporting
Revline Medical Solutions provides medical billing, medical coding, revenue cycle management, denial management, prior authorization, credentialing, and billing audit solutions, with orthopedics listed among the specialties it supports.
For orthopedic practices, specialty-aware coding and billing support can help identify documentation gaps and prevent avoidable claim errors before they become long-term AR.
Final Thoughts
The Orthopedic Billing & CPT Codes Cheat Sheet 2026 should be treated as more than a list of procedure codes.
Successful orthopedic medical billing depends on connecting the correct CPT code with precise ICD-10-CM diagnosis coding, complete documentation, appropriate modifiers, current NCCI edits, authorization requirements, global surgery rules, and payer-specific policies.
For 2026, practices should pay particular attention to updated CPT resources, new musculoskeletal codes such as 27458 and 27713, revised SI joint coding, modifier compliance, and the ICD-10-CM transition occurring on October 1, 2026.
A disciplined coding and revenue cycle process helps orthopedic practices submit cleaner claims, reduce preventable denials, maintain compliance, and protect the revenue generated by the care they provide.
Frequently Asked Questions
1. What are orthopedic CPT codes?
Orthopedic CPT codes are standardized procedure codes used to report medical services provided for musculoskeletal conditions involving bones, joints, muscles, tendons, ligaments, and related structures. They can represent office visits, joint injections, fracture treatment, arthroscopy, joint replacement, spine procedures, imaging, and other orthopedic services. The exact CPT code should always match the procedure documented in the patient’s medical record.
2. What are the most commonly used CPT codes in orthopedic billing?
Frequently used orthopedic CPT codes include 20610 for certain major joint or bursa aspiration/injection procedures, 20611 when qualifying ultrasound guidance is included, 29881 for certain knee arthroscopy procedures, 29888 for ACL reconstruction, 29827 for arthroscopic rotator cuff repair, 27130 for total hip arthroplasty, and 27447 for total knee arthroplasty. Code selection depends on the exact service and documentation.
3. What is the difference between CPT codes 20610 and 20611?
Both codes relate to aspiration and/or injection of a major joint or bursa. CPT 20610 generally applies when ultrasound guidance is not used, while CPT 20611 includes qualifying ultrasound guidance and associated documentation requirements. Providers should verify the full current CPT descriptor and payer rules before billing.
4. How do CPT and ICD-10-CM codes work together in orthopedic billing?
CPT codes describe what service or procedure was performed, while ICD-10-CM codes describe why the service was medically necessary. For example, an orthopedic procedure code may need to be linked to a diagnosis describing osteoarthritis, a fracture, tendon injury, or another musculoskeletal condition. Accurate linkage helps demonstrate medical necessity and reduce claim denials.
5. Why is laterality important in orthopedic medical coding?
Laterality identifies whether a condition or procedure involves the right, left, or sometimes bilateral side of the body. Orthopedic coding frequently requires this level of detail because many ICD-10-CM codes and payer billing rules distinguish between anatomical sides. Missing or conflicting laterality between the diagnosis, procedure, and medical record can lead to claim denials.
6. What modifiers are commonly used in orthopedic billing?
Common orthopedic billing modifiers include RT for the right side, LT for the left side, 50 for qualifying bilateral procedures, 25 for a significant and separately identifiable E/M service, 57 for certain decisions for major surgery, and 59 or X{EPSU} modifiers for distinct services when coding requirements are satisfied. CMS states that modifiers should only be used when the clinical circumstances justify them and not merely to bypass an NCCI edit.
7. What are NCCI edits in orthopedic billing?
The National Correct Coding Initiative (NCCI) includes coding policies and Procedure-to-Procedure edits designed to prevent inappropriate reporting of services that should generally be bundled together. Orthopedic practices should check applicable NCCI edits when multiple procedures are performed during the same encounter. A modifier should only override an edit when the documentation and clinical circumstances support separate reporting.
8. How are fracture ICD-10-CM codes selected in orthopedic billing?
Fracture coding may depend on factors such as the specific bone and location, right or left side, displaced or nondisplaced status, open or closed fracture, healing status, and phase of treatment. Under FY 2026 ICD-10-CM guidance, seventh character A generally represents active treatment, while D is used for routine care during the healing or recovery phase after active treatment has been completed.
9. What is the global period in orthopedic billing?
A global surgical period is a defined period in which certain routine services associated with a surgical procedure are included in the payment for that surgery. Many major orthopedic surgeries have global surgery rules, so routine postoperative services may not be separately payable. Special circumstances may require modifiers such as 24, 58, 78, or 79, depending on the service and payer requirements.
10. What are the most common causes of orthopedic billing claim denials?
Common orthopedic claim denials are caused by missing prior authorization, incorrect CPT or ICD-10-CM codes, CPT-to-diagnosis mismatches, incorrect modifiers, incomplete documentation, NCCI bundling conflicts, eligibility issues, global-period errors, missing laterality, and payer-specific coverage requirements. Regular coding audits, eligibility checks, authorization verification, claim scrubbing, and denial analysis can help identify these problems before they affect reimbursement.