Published in the ICD-10-CM are specific fundamental coding principles that ensure accurate claim submission and help clinicians and their office staff reduce claim denials. Here are a few rules that pertain to retina coding.

CODE TO THE HIGHEST LEVEL OF SPECIFICITY

Medicare and other payers require ICD-10 codes to be billed to the highest level of specificity. For example, Medicare Administrative Contractor Novitas states in its local coverage article A57804 that it is the physician’s “responsibility to select codes carried out to the highest level of specificity and selected from the ICD-10-CM book appropriate to the year” of the encounter.1

Using the AAO's ICD-10-CM For Ophthalmology: The Complete Reference or other resources, always search a diagnosis code by the main term in the alphabetical index, and then verify by cross-referencing the code in the tabular list to ensure you select the most specific code. A dash following ICD-10 codes listed in the alphabetical index indicates there are additional digits to add for a higher level of specificity. ICD-10 codes without the remaining digits are not reportable and will be denied.

For example, dry AMD is listed in the alphabetical index as H35.31-. Under the tabular list, the sixth character is associated with laterality: 1 for right eye, 2 for left eye, and 3 for bilateral involvement. The seventh character is associated with the stage of the disease: 1 for early, 2 for intermediate, 3 for advanced without subfoveal involvement, and 4 for advanced with subfoveal involvement. Thus, intermediate dry AMD in the left eye in order of increasing specification would be reported as:

  • H35.31-, dry AMD
  • H35.312-, dry AMD, left eye
  • H35.3122, dry AMD, left eye, intermediate

PAY ATTENTION TO EXCLUDES1 NOTES

Chapter 7 of the ICD-10-CM includes the diseases of the eye and adnexa and provides subchapters by condition in conjunction with Excludes1 notes for each section. When included, these notes mean the codes provided can’t be billed with the ICD-10 codes in that subchapter.

For example, subchapter H35.4-, peripheral retinal degeneration, includes an Excludes1 note for H33.3-, retinal breaks without detachment. H33.3- codes cannot be billed with those listed in subchapter H35.4-. If these codes were reported together, the payer may deny the claim. Report only the condition that was the primary reason for the visit in these cases.

DON’T REPORT CONDITIONS UNTIL THEY ARE CONFIRMED

Do not report any ICD-10 code associated with the differential diagnoses; wait to report until the correct condition is diagnosed.

APPROPRIATELY LINK CPT CODES TO ICD-10-CM CODES

The ICD-10 code that supports medical necessity for a particular service should be linked correctly to the CPT code on the claim. The ICD-10 codes are listed in item 21 of the claim form (A-L), and the link to the CPT code is designated in item 24e. For example, a patient is seen for a posterior vitreous detachment (PVD), right eye, and retinal tear with multiple breaks, left eye. An examination and laser are billed. The appropriately linked CPT code and ICD-10 code would be:

  • Examination code, 9XXXX – H33.332, H43.811
  • Laser code, 67145 – H33.332

If both the PVD and retinal tear ICD-10 codes are linked to CPT code 67145, the claim may be denied because PVD does not support medical necessity.

Another common claim denial is incorrectly linking laterality to treatment. For an intravitreal injection in the right eye, CPT code 67028, linking a bilateral wet AMD ICD-10 code can prompt a denial. Instead, link CPT code 67028-RT to H35.3211, wet AMD with active choroidal neovascularization, right eye.

ACCESS RESOURCES

AAO members can access valuable ICD-10 resources at aao.org/icd10. The ICD-10-CM For Ophthalmology: The Complete Reference provides all the necessary fundamentals, rules, and ophthalmic ICD-10 codes to code correctly the first time.

1. Billing and coding: scanning computerized ophthalmic diagnostic imaging (SCODI). CMS. Accessed February 27, 2025. www.cms.gov/medicare-coverage-database/view/article.aspx?articleid=57804