You may need to pay a healthcare surcharge (called the ‘immigration health surcharge') as part of your immigration application.
This amount is a single payment and applicants will be charged the annual amount for each year of the maximum period of leave which could be granted under the immigration rules. If the period of leave includes part of a year that is more than 6 months, the full annual amount is payable ie £150 for students and dependants per year. If this period of leave includes part of a year that is 6 months or less, the amount payable for that part of a year is half the specified amount, ie £75 for students and dependants.
Please be aware that the Immigration Health Surcharge will increase to £300/year (or £150 per 6 months) later in 2018. There is no confirmation of the exact date yet.
Note that the Order refers to length of leave, not length of course, so the additional periods at the start and end of a course are taken into account when calculating the immigration health charge.
You will be required to make the payment during the VISA appointment prior to submitting your application.