Managing your health includes understanding the purpose of diagnostic testing, the different types of tests, and factors that influence insurance coverage.
Diagnostic tests are medical tests and procedures that find the cause of symptoms or keep track of health problems. These tests help your doctor figure out what's wrong and what treatment options might work best.
Unlike preventive care, which aims to keep you healthy through routine screenings and check-ups before any symptoms appear, diagnostic care focuses on identifying or managing specific medical concerns.
Understanding this difference is important because insurance often treats preventive and diagnostic services differently.
Diagnostic tests come in many forms, and each one checks your health in different ways.
- Lab tests: Blood work, urine tests, and cultures help find infections, check organ function, and evaluate overall health.
- Imaging tests: These include X-rays, CT scans, MRIs, and ultrasounds. They let doctors see inside your body to diagnose injuries, tumors, or internal issues.
- Screenings: Some tests, like mammograms or colonoscopies, can be used for both prevention and diagnostics. For example, a mammogram done as part of routine screening is preventive, but one done to check a breast lump is diagnostic.
Whether your insurance covers a specific diagnostic test – and whether or not you'll have a copay – depends on several factors, including:
Most insurance plans, including those from Blue Cross and Blue Shield of North Carolina (Blue Cross NC), cover diagnostic tests if a doctor has determined that the test is needed to diagnose or treat a health issue.
Some plans limit how often you can have a specific test unless there's a clear medical reason to repeat it.
Going to labs and imaging centers that are in your plan's network usually has better coverage and lower out-of-pocket costs for you. Going out-of-network could mean higher prices or no coverage at all.
Routine screenings for healthy individuals (like a Pap smear or colonoscopy at recommended intervals) are often fully covered as part of preventive care.
However, if your doctor orders the test because you're having symptoms or have a known risk factor, it may be billed as a diagnostic test, which could involve copays, coinsurance, or deductibles.
Some diagnostic tests, especially more expensive ones like MRIs or CT scans, may require preauthorization from your insurance company. This means your doctor needs to get approval before the test to make sure it qualifies for coverage.
If you don't get approval, your insurance may not cover the test, and you'll have to pay for the cost.
Whether you have an employer-sponsored plan, an individual policy, or plans like Medicare or Medicaid can make a difference in coverage and rules.
Deductibles, copayments, and coinsurance rates will also vary. Be sure to check your plan's benefits to know your coverage.
Planning ahead can help you save money and make the best decisions for you. Before getting any medical test, it's a good idea to:
- Ask your doctor why you need the test.
- Confirm whether it's preventive or diagnostic.
- Check with your insurance company about coverage and any preauthorization requirements.
Our Knowledge Center features helpful articles with simple and reliable information for many of your insurance questions, like how to submit a claim and how to find the right doctor.
Blue Cross and Blue Shield of North Carolina does not discriminate on the basis of race, color, national origin, sex, age or disability in its health programs and activities. Learn more about our non-discrimination policy and no-cost services available to you.
Information in other languages: Español 中文 Tiếng Việt 한국어 Français العَرَبِيَّة Hmoob ру́сский Tagalog ગુજરાતી ភាសាខ្មែរ Deutsch हिन्दी ລາວ 日本語
© 2025 Blue Cross and Blue Shield of North Carolina. ®, SM Marks of the Blue Cross and Blue Shield Association, an association of independent Blue Cross and Blue Shield plans. All other marks and names are property of their respective owners. Blue Cross and Blue Shield of North Carolina is an independent licensee of the Blue Cross and Blue Shield Association.