As Ing_Percy mentioned, it is entirely up to you which path to pursue for the CCNA certification. If you do decide to pursue one of the current CCNA R&S certification paths (either 100-105 ICND1+ 200-105 ICND2 OR single 200-125 CCNA exam) your certifications will have a validity of 3 years. Also, candidates who hold a valid CCNA R&S going into Feb 24, 2020 will automatically receive the new CCNA Certification and a corresponding training badge as well.
So for example - If a candidate decides on the two exam path, passing ICND1 + ICND2, he or she will be certified in CCENT and CCNA R&S, with a validity of 3 years each. Then when the new Cisco certifications program officially begins on Feb 24, 2020, the candidate will receive the new CCNA certification, which will reflect the expiration date of the CCNA R&S certification. So starting Feb 24, the candidate will end up with 3 valid certifications: CCENT, CCNA R&S, and the new CCNA.
Under the new program, the CCENT and CCNA R&S will be retired so it will no longer be possible to recertify those two after Feb 24, 2020. However, you will still be able to maintain the new CCNA certification by completing the necessary recertification requirements before the expiration date.
We wish you the best of luck on whatever certification path you decide to take.
Cisco Learning Network Moderator