“Coding Corner” focuses on coding, compliance, and documentation issues relating specifically to physician billing. This month’s tip comes from the American Academy of Professional Coders’ (AAPC) Brad Ericson, MPC, CPC, COSC. AAPC is one of the nation’s largest and most respected providers of education and professional certification to physician-based medical coders. 

Modifier 33 Preventive service was a last minute addition to CPT® 2011, but it continues to confuse practices providing preventive services under the Patient Protection and Affordable Care Act (ACA). Under the ACA, payors must cover certain preventive services and immunizations, waiving the co-pay and deductible and paying fully for the covered services. 

Append modifier 33 to a code to alert the patient’s payor that you provided the preventive services and cost sharing does not apply. Nearly 60 preventive services falling within the following four categories are to be provided without cost sharing by the patient:

• Services rated “A” or “B” by the U.S. Preventive Services Task Force (USPSTF)
• Preventive care and screenings for children
• Preventive care and screenings provided for women
• Immunizations for routine use in children, adolescents, and adults

Modifier 33 is reported to commercial payors only, and it is appended to all appropriate codes not already designated preventive services. Payors are allowed to require cost sharing for services not covered under the ACA and may choose to not cover services provided out-of-network.

Examples where appending modifier 33 to preventive service codes is not necessary include HCPCS Level II G codes, such as G0103 Prostate cancer screening; prostate specific antigen test (PSA) and some CPT® codes like 77057 Screening mammography, bilateral (2-view film study of each breast). Watch for the words “screening” or “preventive” in the code descriptions.

If you provide multiple preventive medical services to the same non-Medicare patient on the same day, append modifier 33 to the codes describing each preventive service rendered on that day.

You may also apply modifier 33 when a preventive service must be converted to a therapeutic service. “The most notable example of this,” according to CPT® Assistant, “is screening colonoscopy [45378 Colonoscopy, flexible, proximal to splenic flexure; diagnostic, with or without collection of specimen(s) by brushing or washing, with or without colon decompression (separate procedure)] that results in a polypectomy [e.g., 45383 Colonoscopy, flexible, proximal to splenic flexure; with ablation of tumor(s), polyp(s), or other lesion(s) not amenable to removal by hot biopsy forceps, bipolar cautery or snare technique].”

Remember to apply modifier 33 only for commercial carriers. Medicare does not accept modifier 33. If a screening colonoscopy leads to polyp removal for a Medicare patient, report the appropriate removal code, such 45383 Colonoscopy, flexible, proximal to splenic flexure; with ablation of tumor(s), polyp(s), or other lesion(s) not amenable to removal by hot biopsy forceps, bipolar cautery or snare technique, with modifier PT Colorectal cancer screening test; converted to diagnostic test or other procedure rather than modifier 33.