There is no regulation that defines a 6, 8, 12, 14 or 15 panel, and two laboratories selling the same number can be testing for different things. The number tells you how many substance groups are screened and nothing about which ones, so the analyte list and the cutoff levels are the only specification that means anything. This page sets out what larger panels usually add and what each addition costs you in process.
What the numbers usually mean
The federal five are amphetamines, cocaine metabolites, opiates, phencyclidine and cannabinoids. A 6 panel typically adds one group, most often benzodiazepines or barbiturates. Larger panels work outwards through methadone, propoxyphene, methaqualone or a modern substitute, synthetic opioids such as oxycodone and hydrocodone, buprenorphine, tramadol, and sometimes fentanyl. Laboratories differ substantially at the upper end, which is where two 15 panels from different vendors are least likely to be the same test.
Everything above the federal five is prescription territory
This is the practical consequence of buying breadth. Benzodiazepines, barbiturates, opioids, methadone and buprenorphine all appear legitimately in the specimens of people taking prescribed medication, so a wider panel produces more non-negative results that are not policy violations at all. Each of those needs a Medical Review Officer, a licensed physician, to review the result with the donor and determine whether there is a lawful explanation. Buying a 15 panel without MRO capacity means an employer receiving information about employees' medical conditions, which is a very different exposure from enforcing a drug policy.
Choose the panel from the policy
The useful question is not how many substances can be screened but what you would do about each result. If your policy has no answer for a confirmed benzodiazepine positive with a valid prescription, do not screen for benzodiazepines. If your workforce operates machinery and prescription sedation is a genuine safety question, that is a fitness for duty conversation with an occupational health provider rather than a drug policy question, and it needs a different process. The panel should be the last decision, not the first.
Cost is not the reason to choose
The price difference between panel sizes is small next to the collection fee, so panel breadth is rarely a meaningful lever on programme cost. What does move cost is the number of non-negatives, because each triggers confirmatory analysis and Medical Review Officer time. A wider panel is therefore cheaper to buy and more expensive to run, which is the opposite of how it is usually presented. Testing is bought from collection and laboratory networks rather than from the screening providers whose record prices this site carries.
Questions people ask about 6 panel drug test
What is a 6 panel drug test?
Typically the federal five substance groups plus one more, most often benzodiazepines or barbiturates. There is no regulation defining it, so ask for the analyte list and cutoff levels rather than the panel number.
Is a 15 panel better than a 5 panel?
It is broader, not better. Everything above the federal five is largely prescription territory, so a wider panel produces more results that need a Medical Review Officer to interpret and are not policy violations.
Do two 15 panels test for the same things?
Not necessarily. Laboratories differ most at the upper end of the range, so two vendors selling a 15 panel may be screening different analytes at different cutoff levels.
Does a bigger panel cost much more?
The test itself costs a little more, and the programme costs more to run because each non-negative triggers confirmation and Medical Review Officer review. The collection fee dominates the per-test price either way.