With respect to health and medical insurance policies, this refers to the length of time within your policy period that is available for you to satisfy your deductible amounts before you receive benefits for the coverage for which that deductible applies. Most health plans make reference to a calendar year deductible, which defines the accumulation period. A calendar year deductible means that you have from January 1st to December 31st of each year to meet your deductible. At the end of this period, your deductible is reset. For eample, let's say that your medical insurance policy has a $2,000 calendar year deductible that applies only to inpatient hospitalization. This means that you must pay the first $2,000 per year toward any medical epenses related to inpatient hospital admittance. Once you meet that deductible amount, the insurance company will begin paying their share as defined by the coinsurance levels outlined in your policy. This amount resets on the first day of the following year, regardless if you made a contribution to this deductible during the prior year. The accumulation period will be less than 12 months during your first year of coverage, unless your policy first becomes effective on January 1st. If your coverage begins on July 1st, your first year accumulation period is only 6 months, because it resets on January 1st of the following year. Some medical insurance plans will allow for a carry-over on any contributions you make toward your deductible during the last quarter of the year. In these cases, the accumulation period is 15 months. Review your insurance policy thoroughly to understand how the accumulation period applies to your coverage. If you are not certain, ask your insurance broker or contact the customer service department of your insurance company. Knowing the accumulation periods may help you make timely plans for your health care and receive the most benefits from your coverage. If, during any calendar year, you have met your plan deductible, and you have pending medical treatments, such as a planned surgery, you would want this procedure performed before the end of the year. If you wait until the following year, you will need to first meet the deductible before your insurance company pays their percentage.