How often can I order a vitamin D test on Medicare?

Vitamin D testing (item 66608) is restricted to patients who meet specific clinical criteria including osteoporosis, malabsorption, dark skin with limited sun exposure, medications affecting vitamin D metabolism, and chronic renal failure. When clinically indicated, it can be repeated no more than once per 12 months unless the patient is deficient and being treated, in which case retesting to confirm adequacy of replacement is permitted.

What are the Medicare rules for HbA1c testing?

For diagnosed diabetes management, HbA1c (item 66551) can be tested up to 4 times per 12 months. For diabetes screening in high-risk asymptomatic patients, item 73839 is limited to once per 12 months. Point-of-care HbA1c (item 73812) can be claimed up to 3 times per 12 months, with a combined maximum of 4 HbA1c tests total from all sources.

Medicare Investigation Restrictions

Quick reference for pathology and imaging frequency limits, age eligibility, and clinical criteria. Search by test name, item number, or condition.

📋 Source: MBS Online item descriptors and explanatory notes. Medicare compliance guidelines.
Your doctor or healthcare provider knows your history and circumstances — always follow their personalised advice over general information.

📌 This is a general guide only — not a billing or clinical directive. MBS item numbers, rules, and fees change. Always verify at mbsonline.gov.au and confirm eligibility with your practice software.

⚠️ Tier 2 — under reconstruction (May 2026): Several MRI imaging item numbers on this page (63492 head, 63495, 63500/63501 hip, 63509, 63561/63562 knee) appear to be pre-November 2024 numbering that has since been restructured. Vitamin D pathology references item 66608 — the current item is 66833. Until these are individually re-verified against current MBS, treat this page as background context only. Always confirm at mbsonline.gov.au before billing. For complex billing questions, contact the MBS helpline on 13 21 50.

Last updated March 2026. Always verify against MBS Online. This guide covers common GP-initiated investigations — specialist items may have different rules.