Coding corner: Documenting ulcers of the skin

Clear and complete clinical documentation is crucial to coding ulcers, which are sores on the skin or a mucous membrane, accompanied by the disintegration of tissue.

Ulcers can result in complete loss of the epidermis and often other layers of the skin and even subcutaneous fat. They sometimes can be caused by lack of mobility, which causes prolonged pressure on tissue.

Code assignments are based on the type, location, laterality and the stage of severity. They’re also based on any associated underlying conditions, including:

• Diabetes
• Atherosclerosis
• Chronic venous hypertension

The coding guidelines and code assignments for these conditions can be found in Chapter 12 of the ICD-10-CM Official Guidelines for Coding and Reporting manual: Diseases of the Skin and Subcutaneous Tissue (L00-L99).

Here are some tips for coding pressure versus non-pressure ulcers.

Identifying and coding pressure ulcers

Pressure ulcers, also known as pressure sores, pressure injuries, bedsores and decubitus ulcers, are localized damage to the skin and underlying tissue. They usually occur over a bony prominence as a result of pressure or pressure in combination with shear friction.

• Pressure ulcer stages are classified by the severity or progression of the disease:
• Unspecified stage
• The stage of the ulcer isn’t documented.
• Stages 1-4 of pressure ulcer
• Stage 1 — Skin is intact with redness.
• Stage 2 — Shallow, open ulcer with red wound bed. The ulcer has partial thickness and loss of dermis, presenting as a shallow open ulcer with a red pink wound bed without slough.
• Stage 3 — Subcutaneous fat may be visible. Slough may be present at this stage but it doesn’t obscure the depth of tissue loss.
• Stage 4 — Bone, tendon or muscle is exposed. Slough or eschar may be present on some parts of the wound bed.

• Unstageable
• The ulcer is classified as unstageable if the stage of ulcer can’t be clinically determined. The ulcer is covered by slough, eschar or blister, for instance, or has been treated with a skin or muscle graft.
• Pressure ulcers documented as deep tissue injury rather than because of trauma is an example.

• ICD-10-CM contains combination codes to identify the site and the stage of pressure ulcers. Assign as many codes from category L89 as needed to identify all pressure ulcers for the patient.

Below are some examples with category ranges from L89000-L8995.

• Risk factors for pressure or decubitus ulcers include:
• Bedridden patients
• Chronic conditions, including diabetes or vascular disease
• Immobility due to brain or spinal injury
• Wheelchair dependent
• Documentation should be clearly noted on whether the wound is healed or healing.
• An ICD-10-CM code is not assigned when the documentation states the pressure ulcer is completely healed.
• The medical record documentation for healing ulcers should always include the appropriate stage.
• When unable to determine a stage for an ulcer, include a comment for the reason (e.g., eschar).
• Patients admitted to inpatient hospital stay with pressure ulcers
• Assign the code for the site and severity at the time of admission for ulcers that healed at the time of discharge.
• When a pressure ulcer evolves into another stage during the admission:
• Two separate codes should be assigned.
• One code for the site and stage on admission
• A second code for the same ulcer site and the highest stage reported during the stay

Non-pressure chronic ulcers

Official guidelines have been added to ICD-10-CM Official Guidelines for Coding and Reporting FY 2018, Section 1, Chapter 12.b.1.2.3.

Seventy-two codes were added to the categories L97 and L98 that involve muscle or bone without the presence of necrosis. See 2018 updates to ICD-10-CM codes on the Centers for Medicare & Medicaid Services website.**

Below are some examples of category ranges from L97101 through L98499.

• An ICD-10-CM code isn’t assigned when the documentation states the pressure ulcer is completely healed.
• When the condition is described as healing, assign the appropriate non-pressure ulcer code based on the documentation in the medical record.
• Use a code assignment for unspecified severity when the severity of the wound isn’t documented.
• Documentation should be clearly written to identify whether the patient has a new non-pressure ulcer from the one that’s healing. Document so it’s clear there’s another ulcer that’s different from the one the patient is already being treated for.
• Patients admitted to inpatient hospital with a non-pressure ulcer.
• For ulcers present at the time of admission but healed at the time of discharge, assign the code for the site and severity at the time of admission.
• When a non-pressure ulcer evolves into another stage during the admission, two separate codes should be assigned:
• One code for the site and severity level on admission
• A second code for the same ulcer site and the highest stage reported during the stay

Key points to keep in mind

• Clinical documentation should be clearly written for conditions such as wound, sore or skin breakdown so these conditions aren’t confused with ulcers of the skin.
• The associated ulcer diagnosis must be documented in the encounter note by the doctor, even if a nurse documented the pressure stages.
• The stage (1- 4) of progression of the ulcer is always required for pressure or decubitus ulcers.
• When documenting an ulcer, always identify the site, such as the back or lower limb and laterality, such as right or left.
• A completely healed ulcer isn’t coded.
• Documentation should clearly distinguish when an ulcer is healed versus in the healing process.
• Identify when an ulcer being treated is chronic and non-healing.
• Documentation of ulcers during an inpatient hospital stay include:
• The documentation of pressure ulcers if they were present on admission
• Two separate code assignments when an ulcer condition evolves into another stage during hospital stay
• Document all associated underlying conditions such as:
• Gangrene
• Atherosclerosis of the lower extremities
• Chronic venous hypertension
• Diabetes
• Postphlebitic syndrome
• Varicosity

None of the information included in this article is intended to be legal advice and, as such, it remains the provider’s responsibility to ensure that all coding and documentation are done in accordance with all applicable state and federal laws and regulations.

** Blue Cross Blue Shield of Michigan doesn’t own or control this website.