Yes, a Filipino who becomes a US citizen can still return to the Philippines and reacquire their Philippine citizenship by taking an oath of allegiance under the "Citizenship Retention and Re-acquisition Act of 2003" (RA 9225), also known as the Dual Citizenship Law; essentially allowing them to hold both citizenships simultaneously.
Key points about this process:
Natural-born Filipino requirement:
To be eligible, the individual must have been a natural-born Filipino citizen before becoming naturalized as a US citizen.
Application process:
To reacquire Philippine citizenship, one needs to submit necessary documents like a birth certificate, marriage certificate (if applicable), and a Certificate of Naturalization from the US to a Philippine consulate.
Oath of allegiance:
The final step is to take an oath of allegiance to the Republic of the Philippines before a Philippine consular officer.