CIBT is not a visa; it's a company that provides visa services.
US citizens (and citizens from most countries in fact) can enter Indonesia visa free for up to 30 days for tourism and certain other purposes if you meet the requirements. That period cannot be extended. There's also a $35 visa-on-arrival for 30 days, which can be extended once. You can also review the visa information provided by the US State Department. And according to Timatic, the database used by airlines for visa information:
The following are exempt from holding a visa:
Nationals of USA for a maximum stay of 30 days.
This does not apply when traveling for journalism visits.
Nationals of USA can obtain a visa on arrival for a maximum stay of 30
days if their passport contains at least half an unused visa page and
if they have at least USD 1,000.- or a valid credit card. They can
apply to extend their stay for an additional 30 days.
Passengers can apply for a visa on arrival at Balikpapan (BPN), Banda
Aceh (BTJ), Bandung (BDO), Batam (BTH), Denpasar-Bali (DPS), Jakarta
(Halim Perdana Kusuma (HLP) and Soekarno-Hatta (CGK), Kupang (KOE),
Lombok (LOP), Medan Kuala Namu (KNO), Makassar (UPG), Manado (MDC),
Padang (PDG), Palembang (PLM), Pekan Baru (PKU), Pontianak (PNK),
Semarang (SRG), Surabaya (SUB), Surakarta (Solo) (SOC) or Yogyakarta
Passengers exceeding their permitted stay will be fined (Note: The day
of arrival in Indonesia is counted as the first day of stay).
If you are staying for a purpose that requires a visa or staying longer than the visa free period, you'll need to obtain a visa in advance. You can use a service like CIBT to assist in that process, or apply for one yourself through the Indonesian Consulate.