Avoid making some of the biggest errors that MACs see. A lax approach to documenting time for your prolonged services encounters could land you in hot water with the feds. So indicated Part B MAC National Government Services in a May 24 education session, "Medical Review Error Webinar," which laid bare issues that NGS found to be chronically miscoded, with tips on how to avoid making the same errors. Prolonged Services Often Misbilled, NGS Notes The payer found that a common error among Part B practices was that documentation did not support the medical necessity for prolonged E/M service codes. "Prolonged services of less than 30 minutes total duration on a given date are not separately reported," the NGS rep noted. She reminded practices that although time spent with the patient does not need to be continuous, it must be clear and accurately documented in the medical record. You'll report +99354 for the first hour, followed by +99355 for each additional 30 minutes. Example: Code it: NGS Focuses on Chiropractic Errors NGS reminded chiropractic practices during the call that they must list two diagnoses on every claim -- the precise level of subluxation listed as the primary diagnosis, followed by the resulting disorders listed thereafter. In many cases, diagnoses listed on Part B claims are "insufficient to support medical necessity," the NGS rep noted. The facts: In addition, Medicare and most private insurers require a diagnosis of subluxation of the spine to demonstrate medical necessity for CMT billing. "The precise level of subluxation must be specified through use of the appropriate diagnosis code(s) on the claim," notes a policy from Palmetto GBA, a Part B payer in eight states. "Secondary diagnoses must be present on the claim to indicate the significant neuromuscular health problem necessitating treatment," the policy indicates. A similar policy from Noridian Medicare, another Part B MAC, advises chiropractors to enter up to four diagnosis codes in priority order (two primary and two secondary conditions). "If you need to document more than four diagnosis codes, as will be the case any time there are more than two regions billed, the additional diagnoses must be present in the medical record," the policy states. Here's how: In black and white: Keep an Eye on Medical Necessity for Labs The most common errors among diagnostic labs was that the documentation did not support the number of services submitted, that the lab failed to support medical necessity, and were unable to support the order for the services, the NGS reps noted. Reminder: Lab requisition forms should be designed to capture the correct information to promote appropriate ordering of tests. For example, when ordering a Pap smear, the form should prompt the treating physician to designate whether it is a diagnostic test or screening test and inform the physician of the frequency constraints for screening tests. The requisition should also require the physician to submit diagnosis information as documentation of medical necessity. If the treating physician doesn't accurately record the reason for the test, whether that be screening, presenting signs and symptoms, or known medical condition, the coder cannot apply the correct diagnosis code. A vague sign or symptom is a perfectly acceptable reason for a test. Physicians need to know that it's acceptable to write down "abdominal pain" as a diagnosis if they don't know if the patient has gastroenteritis, colitis or appendicitis before performing the diagnostic tests.