Short answer. One year. Article 95 entitles every employee who has rendered at least one year of service to a yearly service incentive leave of five days with pay. The entitlement then recurs each year, and several categories of employee and establishment are excluded from it.
What the law says
Every employee who has rendered at least one year of service shall be entitled to a yearly service incentive leave of five days with pay.
Labor Code, Article 95 — Service Incentive Leave. Read the full provision →
A year of service, then every year after
The one-year requirement is a threshold, not a waiting period repeated annually. Once you have rendered at least one year of service the leave is yearly, so it accrues again for each subsequent year rather than having to be re-earned from scratch. Nothing in the clause makes the entitlement depend on the type of contract, the job title, or whether the year was worked continuously in the same position, and an employer that grants it only to some ranks is drawing a line the article does not draw.
It is leave with pay, and unused days are not simply lost
The five days are with pay, which means taking them costs you nothing in wages. Where the days are not used within the year, the common and correct practice is to convert the unused balance to its cash equivalent rather than to cancel it, and an employee who leaves is entitled to be paid for what has accrued and gone unused. A policy that forfeits the leave at year end, or that requires you to take it at a time when the business will never allow it, is worth questioning.
Who is left out
The article excludes those already enjoying the benefit, those enjoying vacation leave with pay of at least five days, employees of establishments regularly employing fewer than ten employees, and establishments exempted by the Secretary of Labor and Employment after considering their viability or financial condition. The small-establishment exception is the one most often invoked, and it rests on a headcount that is checkable. Exemption by the Secretary is a formal act, not something an employer can assume for itself because business is difficult.
Working out what you are owed
Start from your hire date and count the completed years, then look for how each year's five days were treated: taken, converted, or neither. Payslips, leave records and the employee handbook will usually show it, and where nothing appears at all the entitlement has simply gone unpaid. Note that the article also says benefits granted in excess of the five days are not a subject of arbitration or court action, so the claim is anchored on the statutory five rather than on a richer company scheme.