Short answer. Yes. The Solo Parents' Welfare Act ties the benefits to actually being left alone with parenthood. It provides that a change in your status or circumstance, such that you are no longer left alone with the responsibility of parenthood, terminates your eligibility for these benefits. The status is not permanent; it follows your real situation.
What the law says
A change in the status or circumstance of the parent claiming benefits under this Act, such that he/she is no longer left alone with the responsibility of parenthood, shall terminate his/her eligibility for these benefits.
RA 8972, Section 3 — Who Counts As Solo Parent. Read the full provision →
Eligibility follows the situation, not a label
The law defines a solo parent by the reality of raising a child alone, so the status can end when that reality changes. The definition states plainly: a change in the status or circumstance of the parent claiming benefits under this Act, such that he/she is no longer left alone with the responsibility of parenthood, shall terminate his/her eligibility for these benefits. If a detained spouse returns, a separation reconciles, or you marry and now share parenthood with a partner, the ground that made you a solo parent is gone, and with it the entitlement. Being a solo parent, for this law, is a condition you are in, not a title you keep.
The law has since been broadened, check RA 11861
Important update: the original Solo Parents' Welfare Act has been expanded. Republic Act 11861 (2022), the Expanded Solo Parents Welfare Act, widened who qualifies as a solo parent, eased the service requirement for parental leave, and added benefits such as a discount and VAT exemption that the older text does not contain. So while the basic logic still holds, that the benefits attach to your being solo, the categories of who counts, and the benefits available, should be read under RA 11861, not only the earlier definition. Treat the older list as the floor, and check the current statute for the up-to-date terms.
Who the definition originally covered
Under the original definition, a solo parent included a range of situations: a parent left alone by the death, detention, physical or mental incapacity, legal or de facto separation, annulment or abandonment of a spouse; an unmarried mother or father who chose to keep and rear the child; any person who solely provides parental care and support; and a family member who becomes head of the family through a parent's death, abandonment or prolonged absence. Each shares one thread, someone carrying the responsibility of parenthood alone. When that solitary responsibility ends, so does the classification the benefits depend on.
What ending the status does and does not mean
Losing the status going forward is not the same as being punished for the past. Termination means you stop being entitled to the benefits once you are no longer solo; it does not by itself claw back help you validly received while you qualified. It also does not erase your standing forever, since if you later fall back into a qualifying situation, you may qualify again. Because eligibility tracks your circumstances and the rules now sit under the expanded law, anyone unsure whether a change in their household ends or restores the status should have it assessed against RA 11861's current terms.