If insured by your employer and your spouse's employer which is the primary insurance?

Your insurance through your employer is your primary insurance, and your spouse's primary insurance is through his/her employer. If both husband and wife are insured on both insurance policies, then you have primary and secondary coverage. But you will still have to pay any deductibles and co-pays before either policy will pay. The deductible is the amount you first have to pay (usually at the first of the year) before the insurance will pay anything. The co-pay is your percentage of what the insurance doesn't pay, which for many health insurance companies is 80% for them and 20% for you. There is sometimes a co-insurance that you have to pay also. Ex: Insurance companies have a set amount that they pay for any office visit, procedure, etc. If the bill is over what the insurance pays, then you are responsible for the balance.