Short answer. Yes. Article 2265 of the Civil Code provides that the right of retention over real or personal property arising after the Code's effectivity extends to things that came into the creditor's possession before that date. Pre-Code possession is expressly included within the right of retention under the new Code.
What the law says
The right of retention of real or personal property arising after this Code becomes effective, includes those things which came into the creditor's possession before said date.
Civil Code, Article 2265 — Retention Rights After Effectivity. Read the full provision →
Pre-Code possession is covered
Article 2265 of the Civil Code addresses a transitional question: does the right of retention under the new Code apply to property that came into someone's possession before the Code took effect? The answer is yes. The article provides: The right of retention of real or personal property arising after this Code becomes effective, includes those things which came into the creditor's possession before said date. The date on which possession began — whether before or after the Civil Code's effectivity — does not determine whether the right of retention applies. What matters is that the right itself arises under the new Code; when that happens, it covers property in the creditor's possession regardless of when possession started.
What the right of retention means
The right of retention is the right to hold on to property belonging to a debtor until the debtor satisfies a debt or obligation connected to that property. It is a form of security: the party in possession — the creditor — refuses to return the property until the debt owed to them is paid. For a possessor who has made improvements on land before the Civil Code took effect and is now asked to return the land to the owner, the right of retention allows the possessor to withhold delivery until the owner reimburses the cost of those improvements. Article 2265 ensures that this right extends to property already in hand before the new Code arrived.
Both real and personal property are covered
Article 2265 applies to both real property — land and buildings — and personal property — movables of all kinds. The article does not distinguish between the two. Whether the property you have held since before the Code's effectivity is a parcel of land on which you built structures, or a movable object on which you performed repairs, the rule is the same: if the right of retention arises under the new Civil Code, that right encompasses what you have held since before the Code's effective date. The breadth of the article prevents a narrow interpretation that would exclude pre-Code possessions from the protections the new law provides.
The right arises under the new Code, not the old
Article 2265 specifies that the right of retention it covers is one arising after this Code becomes effective. The article does not revive or preserve rights that arose and were extinguished under the old regime. Rather, it clarifies that a right of retention that comes into existence under the Civil Code — because the debt it secures, or the triggering obligation, arose after the Code's effectivity — will reach back to include property already in the creditor's possession. If your situation involves a claim for reimbursement of improvements, the right of retention arises from the Code's provisions on improvements, and under Article 2265 it covers the land you have held since before that date.