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  • Back to the Basics: Testing Services, Part 2

    Modifier Applications

    Modifiers -RT, -LT, -50 Bilateral, -52 Reduced Service, -GA

    The majority of testing services are inherently bilateral, which means that payment is the same whether one or both eyes are tested. Unless a payer has a published unique policy stating otherwise, there is no need to append modifiers -RT for right eye, -LT for left eye or modifier -52 for reduced services when only one eye is examined.

    Tests with unilateral payment or payment for one eye, should be submitted with either modifier -RT or -LT. You should only bill for the eye that has that pathology. Ophthalmology and optometry are the only professions that still have a few tests with unilateral coverage.

    If pathology is in both eyes, depending on the payer requirement, submit with modifier -50 or two lines with modifiers -RT and -LT. Correct payment is 200% of the allowable. There is no 50% reduction for the second eye.


    • 76510 Ophthalmic ultrasound, diagnostic; B-scan and quantitative A-scan performed during the same patient encounter
    • 76511 quantitative A-scan only
    • 76512 B-scan (with or without superimposed non-quantitative A-scan)
    • 76516 Ophthalmic biometry by ultrasound echography, A-scan
    • The professional component (26) of 76519 Ophthalmic biometry by ultrasound echography, A-scan with intraocular lens power calculation and 92136 Ophthalmic biometry by partial coherence interferometry with intraocular lens power calculation
    • 76519 Ophthalmic ultrasonic foreign body localization

    When it’s time to review the CPT code, it will lose unilateral payment.

    Modifier -26 Professional service

    When a patient is in the hospital or skilled nursing facility (SNF) and undergoes a test in your office, you should only submit the professional component (-26) of the test. It is as if the hospital or SNF owns the equipment.

    If you didn’t do due diligence and ask if the patient is currently hospitalized or in a SNF and submitted the test without modifier -26, it may be paid. But as soon as the patient is released, the payer will request repayment of not just the technical component but full payment. This rule does not impact physician performed tests that do not have a -TC/-26 component.

    Modifier – GA Advance Beneficiary Notice

    One of the uses of the advance beneficiary notice (ABN) is when you are not sure of coverage for a Part B patient, either by frequency or by a diagnosis.


    A Medicare patient complains of visual field loss during one of their “blinding” headaches. The ophthalmologist orders a full-field 30-2 OU. There is not a published policy and you are not sure that ICD-10 codes from the headache family are a covered benefit. You wisely obtain an ABN ( and submit 92083 -GA. Modifier -GA conveys to Medicare that you have an ABN on file and the patient recognizes they may be responsible for payment. If you neglect to append modifier -GA and the claim is denied, the remittance advice to the patient will say, “You should have been told that Medicare will not pay for this service. Therefore, you are not responsible for payment.

    Performance During Post-Op

    All medically necessary testing services whether related or unrelated are payable within the global period. No modifier is required.


    Whether published or not, each payer has frequency edits for each test. Performance is not tracked by physician but by patient.

    A good rule to follow is that if you know you are going to refer, or if you are not the treating physician, then do not perform the test. Allow the treating physician to order and perform the test.


    Under Palmetto’s ophthalmoscopy and fundus photography local coverage determination, it reads, “… Baseline photos to document a condition that is reasonably expected to be static and/or not require future treatment would not be medically necessary. Such photos to provide a means of comparison to detect, for example, potential progression of diabetic retinopathy, advanced non-neovascular (dry) macular degeneration with ‘suspicious’ areas, or a nevus or other tumor could be medically necessary. Repeat fundus photography should only be performed at clinically reasonable intervals (i.e., consistent with a noted change on examination or after sufficient time has elapsed for progression or for a treatment to have reasonably had an impact).”


    Medicare Part B publishes local coverage determinations (LCDs) and local coverage articles (LCAs) throughout the year. Other payers publish similar policies on their websites. The content of the LCDs and/or LCAs provide documentation guidelines for which you will be held accountable in an audit. 

    For convenience, the Academy tracks Medicare policies at The only way you can stay compliant is by participating in the payer’s email communication. When a policy is published, the payer has fulfilled their obligation to inform you. It is vital that at least one person in the office is responsible to receive these emails and make changes in the practice as needed. 

    LCDs and LCAs also provide a list of covered diagnoses. Unfortunately, there is no one list of links to ICD-10 to CPT codes that each payer recognizes. 

    It is also imperative that you never take one payer’s rules and apply it to another payer. Each payer, can and does have its own policies.