ASC Coding Guidelines You Need To Know For 2024 Billing

In medical billing, ASC (Ambulatory Surgery Centers) is an entirely separate department. Their processes are strictly under the control of Medicare and thus people operating in this facility comply with their set rules only. Similarly, ASC coding shows little deviation from normal coding guidelines. Codes used in ASC billing and coding are unique and need to be understood carefully.

Here we will dive into this special medical department. Our guide will help you know the intricacies of ASC coding along with how their billing process works. 

So if you are someone associated with this department or just want to gain knowledge, let us break the ASC in medical terms to make it easy to understand.

What is ASC?

The term ASC in the medical industry stands for Ambulatory Surgery Center. This is a type of healthcare facility that provides same-day care for surgeries including diagnosis and preventive procedures. 

ASCs are different from hospitals because they focus on conducting patient surgeries within a day after admission, and they don’t require an overnight stay.

As we discussed, these centers work under the strict checks and balances of Medicare and it has a huge impact on ASC billing and coding processes.

ASC Coding

Despite the influence of Medicare, ambulatory surgery centers are run on specific codes just like in other healthcare departments. Each code defines a unique medical condition for the patients and thus it helps in accurate ASC coding. 

Here is a comprehensive list of top codes used in ambulatory centers.

1. HCPCS Codes

HCPCS defines medical procedures and services for patient billing. These codes fall under two categories:

Level I: It consists of CPT codes that come in handy for medical, surgical, and diagnostic procedures. These codes are controlled by AMA.

Level II: It consists of alphanumeric codes for non-physician medical services like:

• Ambulance
• Durable medical equipment
• Prosthetics
• Orthotics
• Medical supplies

Examples of HCPCS Level II codes used in ASCs:

• A4550: Surgical trays
• J3490: Unclassified drugs
• E1399: Durable medical equipment, miscellaneous
• A4215: Needle, sterile, any size, each
• A4649: Surgical supply; miscellaneous
• C1713: Anchor/screw for opposing bone-to-bone or soft tissue-to-bone (implantable)
• J0881: Injection, darbepoetin alfa, 1 microgram (non-ESRD use)
• J2250: Injection, midazolam hydrochloride, per 1 mg
• L8680: Implantable neurostimulator electrode, each
• Q4100: Skin substitute, FDA cleared as a device, not otherwise specified
• P9045: Albumin (human), 5%, 50 ml
• G0260: Injection procedure for sacroiliac joint; provision of anesthetic, steroid, and/or other therapeutic agent
• J2783: Injection, rasburicase, 0.5 mg
• A4641: Radiopharmaceutical, diagnostic, not otherwise classified
• A7020: Interface for cough stimulating device, includes all components, replacement only
• C2624: Intraocular lens, phakic
• E0720: Transcutaneous electrical nerve stimulation (TENS) device, two lead, localized stimulation
• J0178: Injection, aflibercept, 1 mg

2. CPT Codes

CPT codes describe medical procedures conducted by healthcare professionals in detail. In ASC coding, these codes are extensively used for diagnostic and surgical processes.

Examples of CPT codes commonly used in ASCs:

• 66984: Extracapsular cataract removal with insertion of intraocular lens prosthesis
• 43235: Upper gastrointestinal endoscopy, diagnostic
• 29881: Arthroscopy, knee, surgical; with meniscectomy (medial or lateral, including any meniscal shaving)
• 20610: Arthrocentesis, aspiration, and/or injection; major joint or bursa (e.g., shoulder, hip, knee, subacromial bursa)
• 27447: Arthroplasty, knee, condyle, and plateau; medial and lateral compartments with or without patella resurfacing (total knee arthroplasty)
• 29827: Arthroscopy, shoulder, surgical; with rotator cuff repair
• 30520: Septoplasty or submucous resection, with or without cartilage scoring, contouring, or replacement with graft
• 43239: Esophagogastroduodenoscopy (EGD) with biopsy, single or multiple
• 45380: Colonoscopy, flexible; with biopsy, single or multiple
• 47562: Laparoscopy, surgical; cholecystectomy
• 49505: Repair of inguinal hernia, age 5 years or older; initial, reducible
• 62323: Injection, including indwelling catheter placement, continuous infusion or intermittent bolus, of diagnostic or therapeutic substance(s) (including anesthetic, antispasmodic, opioid, steroid, other solution), epidural or subarachnoid; cervical or thoracic
• 64721: Neuroplasty and/or transposition; median nerve at the carpal tunnel
• 67904: Repair of blepharoptosis; (e.g., ptosis surgery)
• 69436: Tympanostomy (requiring insertion of ventilating tube), general anesthesia
• 70450: CT scan, head or brain; without contrast material

3. ICD Codes

These codes are used to define diagnosis and patient conditions in the bill. ICD has two versions:

• ICD-10-M: Used for diagnostic codes
• ICD-10-PCS: Used for inpatient coding, but not typically used in ASC billing and coding

Examples of ICD-10-CM codes used in ASCs:

• S83.241A: Other tear of medial meniscus, current injury, right knee, initial encounter
• K21.9: Gastro-esophageal reflux disease without esophagitis
• H25.13: Age-related nuclear cataract, bilateral
• M23.50: Chronic instability of the knee, unspecified knee
• H40.11X2: Primary open-angle glaucoma, moderate stage
• K80.20: Calculus of gallbladder without cholecystitis, without obstruction
• N20.0: Calculus of kidney
• J34.2: Deviated nasal septum
• G56.01: Carpal tunnel syndrome, right upper limb
• L40.59: Other psoriatic arthropathy
• H26.9: Unspecified cataract
• S72.001A: Fracture of unspecified part of neck of right femur, initial encounter for closed fracture
• L98.491: Non-pressure chronic ulcer of skin of other sites with muscle involvement without evidence of necrosis
• M19.90: Unspecified osteoarthritis, unspecified site
• S83.401A: Sprain of unspecified site of the right knee, initial encounter
• K64.4: Residual hemorrhoidal skin tags
• H81.12: Benign paroxysmal vertigo, left ear
• I83.813: Varicose veins of bilateral lower extremities with pain
• H52.13: Myopia, bilateral
• R07.9: Chest pain, unspecified
• F41.1: Generalized anxiety disorder
• M54.5: Low back pain

4. Revenue Codes

These are comparatively less significant codes in billing processes but they categorize the type of services given to the patient. It helps in the proper allocation of charges in the bill and is often used in ASCs.

Examples of revenue codes used in ASCs:

• 360: Operating Room Services
• 490: Ambulatory Surgical Care
• 710: Recovery Room

Modifiers Used in ASC

Besides basic billing codes, there are other numeral combinations that make the bill more comprehendible, i.e. Modifiers. 

These are additional codes that represent that medical treatment or process was altered due to some circumstances but doesn’t bring a change to its specific medical code.

In short, modifiers help us understand the scenario in which the medical treatment was given. Some common modifiers used in ASC coding are:

• SG: Procedure performed at an ASC
• LT: Left side (used to identify procedures performed on the left side of the body)
• RT: Right side (used to identify procedures performed on the right side of the body)
• 59: Distinct procedural service
• SG: Indicates a procedure performed at an ASC.
• LT: Procedure performed on the left side of the body.
• RT: Procedure performed on the right side of the body.
• 59: Distinct procedural service.
• 51: Multiple procedures performed in the same session.
• 50: Bilateral procedure.
• 25: Significant, separately identifiable E/M service on the same day as another procedure.
• 78: Unplanned return to the operating/procedure room for a related procedure during the postoperative period.
• 79: Unrelated procedure or service by the same physician during the postoperative period.
• XE: Separate encounter.
• XS: Separate structure.
• XP: Separate practitioner.
• XU: Unusual non-overlapping service.

ASC Billing and Coding Guidelines to Keep in Mind

Since ASC works differently than other departments, there are certain things to consider when working as a biller or coder in these centers. Accurate coding will help you comply with Medicare rules as well as conduct efficient billing. 

Let’s have a look at top ASC coding considerations to optimize your billing:

Use Correct Procedure Codes

Make sure to use specific HCPCS, CPT, and other codes for ASC patients. Don’t forget to use the latest codes with updated revisions.

Apply Appropriate Modifiers

Modifiers like SG, LT, and RT are crucial in defining complete surgical and diagnostic procedures. Use accurate modifiers in the bill to prevent claim denials and loss of revenue.

Follow Medicare Guidelines

Medicare strictly monitors the billing and coding process of ASCs. So you must follow their guidelines including the implementation of the right procedure code.

Accurate Documentation

Carefully conduct the patient documentation and list each medical service with precision. Ensure that the document justifies the use of each code and modifier.

Stay Updated With Code Changes

As in all healthcare facilities, spend proper time getting to know the latest code updates. Regularly visit and update responsible sites. Subscribe newsletters to get the updates so that you can start implementing them as soon as they come into application.

Mastering ASC Coding

If you observe closely, ASC coding is no different than other coding. However, some codes and procedures make it distinct from other healthcare departments. 

You must keep an updated knowledge of all the codes used in the ASC billing and coding to optimize your revenue collection. 

Also, without having a guideline you will be a lost fish in the sea. So learn all the codes used specifically in ambulatory centers and generate an ample amount of revenue while complying with Medicare.